Jaspreet Singh | Aston University (original) (raw)
Papers by Jaspreet Singh
Clinical Therapeutics, 2002
Subsets of psychiatric patients gain excess body weight while receiving mood-stabilizing agents s... more Subsets of psychiatric patients gain excess body weight while receiving mood-stabilizing agents such as lithium carbonate or valproate sodium. Patients who gain excess weight may discontinue therapy, with severe consequences. Among the newer anticonvulsant agents, topiramate is a candidate agent for bipolar disorder and is associated with weight loss when used as adjunctive treatment. This open-label, nonrandomized, chart-review study assessed changes in body weight and body mass index (BMI) in patients receiving topiramate, lithium, or valproate. Data were extracted from the medical charts of patients admitted in 1999 and 2000 to a state psychiatric hospital with either schizophrenia, schizoaffective disorder, bipolar disorder, or other psychiatric diagnoses who were prescribed valproate, lithium, or topiramate and were reviewed for changes in body weight and BMI. The use of concomitant psychotropic medicines was recorded (eg, antipsychotic agents, antidepressant agents, other mood stabilizers such as gabapentin or carbamazepine). Continuous variables were analyzed using a factorial analysis of variance and the Student t test. Contingency statistics were used to analyze categorical variables. A total of 214 patients were included in the chart review (123 men, 91 women; mean age, 39.4 years). Significantly more women than men received topiramate (P = 0.004). Patients receiving either lithium or valproate gained a mean (SD) of 6.3 (9.0) kg and 6.4 (9.0) kg, respectively, whereas patients receiving topiramate lost a mean 1.2 (6.3) kg (F = 11.54, df = 2,198; P < 0.001). Lithium- or valproate-treated patients experienced an increase in BMI (mean, 2.1 [3.0] for both groups), whereas topiramate-treated patients experienced a reduction in BMI (mean, -0.5 [2.4]); this result was statistically significant (F = 11.40, df = 2,198; P < 0.001). Finally, lithium- or valproate-treated patients gained >8% of their baseline body weight (8.2% [11.5%] for lithium-treated patients and 8.5% [11.9%] for valproate-treated patients), whereas topiramate-treated patients lost 0.7% (7.2%) of their body weight (F = 9.93, df= 2,198; P < 0.001). Controlled studies for the efficacy of topiramate therapy in various psychiatric conditions are awaited. These data indicate that patients receiving topiramate experience body weight loss and a reduction in BMI. This advantage of topiramate may promote long-term adherence to treatment among psychiatric patients and possibly decrease the medical risks associated with obesity.
Harvard Review of Psychiatry, 1994
The autoimmune basis for schizophrenia has been investigated for the last 60 years. Although nume... more The autoimmune basis for schizophrenia has been investigated for the last 60 years. Although numerous immune abnormalities have been reported, the current literature is viewed with much skepticism because most of the studies have failed to control for extraneous factors that may have influenced the findings. Principally, antipsychotic medication, duration of illness, and current clinical state (acutely psychotic or remitted) may considerably alter immune response, as may other factors such as nutritional status, substance abuse, and concurrent medical illness. We review recent studies that employed current diagnostic criteria and modern immunologic techniques. (These studies were located by use of a Medline search on the terms schizophrenia and psychosis, cross-referenced with immune abnormalities, lymphokines, antibodies, lymphocytes, HLA, and medication, and by perusing the reference lists in the articles found through this search.) Immune abnormalities that have been replicated in studies of schizophrenic patients include increased prevalence of antinuclear antibodies, decreased production of interleukin-2, and increased serum concentrations of interleukin-2 receptor and interleukin-6. Given the current importance of autoimmunity as an etiologic mechanism in several branches of medicine, further studies are needed, especially those having a longitudinal design and including drug-naive patients.
Single-walled carbon nanotubes (CNT) are mechanically robust graphene cylinders with a high aspec... more Single-walled carbon nanotubes (CNT) are mechanically robust graphene cylinders with a high aspect ratio that are comprised of sp 2 -bonded carbon atoms and possessing highly regular structures with defined periodicity. CNT exhibit unique mechanochemical properties that can be exploited for the development of novel drug delivery platforms. We hypothesized that novel prototype nanostructures consisting of biologics, radionuclides, fluorochromes, and CNT could be synthesized and designed to target tumor cells. Methods: Tumor-targeting CNT constructs were synthesized from sidewall-functionalized, water-soluble CNT platforms by covalently attaching multiple copies of tumorspecific monoclonal antibodies, radiometal-ion chelates, and fluorescent probes. The constructs were characterized spectroscopically, chromatographically, and electrophoretically. The specific reactivity of these constructs was evaluated in vitro by flow cytometry and cell-based immunoreactivity assays and in vivo using biodistribution in a murine xenograft model of lymphoma. Results: A soluble, reactive CNT platform was used as the starting point to build multifunctional constructs with appended antibody, metal-ion chelate, and fluorescent chromophore moieties to effect specific targeting, to carry and deliver a radiometal-ion, and to report location, respectively. These nanoconstructs were found to be specifically reactive with the human cancer cells they were designed to target in vivo in a model of disseminated human lymphoma and in vitro by flow cytometry and cell-based immunoreactivity assays versus appropriate controls. Conclusion: The key achievement in these studies was the selective targeting of tumor in vitro and in vivo by the use of specific antibodies appended to a soluble, nanoscale CNT construct. The ability to specifically target tumor with prototype-radiolabeled or fluorescent-labeled, antibody-appended CNT constructs was encouraging and suggested further investigation of CNT as a novel delivery platform.
Journal of Clinical Psychiatry, 2005
Obesity is common in persons with schizophrenia. Besides its adverse health effects, obesity redu... more Obesity is common in persons with schizophrenia. Besides its adverse health effects, obesity reduces quality of life and contributes to the social stigma of schizophrenia. This 14-week, multicenter, open-label, rater-blinded, randomized study evaluated the effects of a group-based behavioral treatment (BT) for weight loss in overweight and obese stable patients with DSM-IV schizophrenia or schizoaffective disorder who had been switched from olanzapine to risperidone. Participants were randomly assigned to receive BT or usual clinical care (UC). BT included 20 sessions during which patients were taught to reduce caloric intake. In UC, patients were encouraged to lose weight but received no special advice about weight reduction. The primary outcome measure was change in body weight. Seventy-two patients were enrolled. The mean +/- SD weight loss at endpoint was significant in both groups (p < .05) and numerically greater in patients receiving BT than in those receiving UC (-2.0 +/- 3.79 and -1.1 +/- 3.11 kg, respectively). More patients in the BT group than in the UC group had lost > or = 5% of their body weight at endpoint (26.5% [9/34] and 10.8% [4/37], respectively; p = .082). A post hoc analysis of patients attending at least 1 BT session showed that significantly more patients in the BT than the UC group had lost > or = 5% of their body weight at endpoint (32.1% [9/28] vs. 10.8% [4/37], respectively, p = .038) and at week 14 (complete population; 40.9% [9/22] and 14.3% [4/28], respectively, p = .027). BT may be an effective method for weight reduction in patients with chronic psychotic illness.
Food Hydrocolloids, 2007
Effect of some common chemical modifications such as acetylation, hydroxypropylation and cross-li... more Effect of some common chemical modifications such as acetylation, hydroxypropylation and cross-linking on the physico-chemical, morphological, thermal and rheological properties of starches from different botanical sources have been reviewed. The distinguishing factors that affect the efficiency of modification are the starch source, amylose to amylopectin ratio, granule morphology, and type and concentration of the modifying reagent. The extent of alteration in the starch properties reflects the resistance or the susceptibility of a starch towards different chemical modifications. Modified starches with desirable properties and degree of substitution can be prepared by critically selecting a suitable modifying agent and a native starch source. r
Starch-starke, 2004
Corn starch and starches separated from different potato cultivars were acetylated to evaluate th... more Corn starch and starches separated from different potato cultivars were acetylated to evaluate the effect of plant source on the physicochemical, morphological, thermal, rheological, textural and retrogradation properties of the starches. Corn starch showed a lower degree of acetylation than potato starches under similar experimental conditions. The degree of acetylation for different potato starches also differed significantly. Morphological examination revealed that the granules of acetylated Kufri Chandermukhi and Kufri Sindhuri starches tended to appear as fused and less smooth than native starch granules. Acetylation of corn and potato starches decreased the transition temperatures and enthalpy of gelatinization and increased swelling power and light transmittance. However, the change in these was greater in the potato starches with higher percentage of small sized granules. Acetylated starches showed higher peak G',G'' and lower tan δ than their counterpart native starches during heating. Among the starches from different cultivars, the change in the rheological parameters after acetylation differed to a significant extent. The retrogradation was observed to be negligible in the acetylated cooked starch pastes. Results implied that the change in functional properties of starches with acetylation depends on source and granule morphology of native starch.
Food Chemistry, 2004
The physicochemical, morphological, thermal and rheological properties of acetylated corn and pot... more The physicochemical, morphological, thermal and rheological properties of acetylated corn and potato starches, prepared using acetic anhydride at different levels (412 g), were compared. Corn starch showed lower acetyl (%) and degree of substitution (DS) than ...
Food Chemistry, 2001
The starches separated from five different Indian potato cultivars (Kufri Chandermukhi, Kufri Bad... more The starches separated from five different Indian potato cultivars (Kufri Chandermukhi, Kufri Badshah, Kufri Jyoti, Kufri Sindhuri and S1) were investigated for morphological, thermal, rheological, turbidity and water-binding properties. The starch separated from all the five ...
Food Chemistry, 2003
Morphology, thermal and rheological properties of starches from maize mutants deficient in starch... more Morphology, thermal and rheological properties of starches from maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were studied and compared with the wild type. SSIII deficiency reduced granule size of the starches from 16.7 to ~11 μm (volume-weighted mean). Thermal analysis showed that SSIII deficiency decreased the enthalpy change of starch during gelatinization. Steady shear analysis showed that SSIII deficiency decreased the consistency coefficient and yield stress during steady shearing, while additional deficiency in granule-bound starch synthase (GBSS) increased these values. Dynamic oscillatory analysis showed that SSIII deficiency decreased G' at 90 oC during heating, and increased it when the paste was cooled to 25 oC at 40 Hz during a frequency sweep. Additional GBSS deficiency further decreased the G'. Structural and compositional basis responsible for these changes in physical properties of the starches are discussed. This short communication highlighted the relationship between SSIII and some physicochemical properties of maize starch.
Carbohydrate Polymers, 2004
Starches separated from four potato cultivars were hydroxypropylated and their physico-chemical, ... more Starches separated from four potato cultivars were hydroxypropylated and their physico-chemical, morphological, thermal and rheological properties were compared. The extent of hydroxypropylation measured as molar substitution differed significantly among the starches from different potato cultivars. Kufri Jyoti hydroxypropylated starch showed highest molar substitution, while Kufri Chandermukhi hydroxypropylated starch showed the lowest. The hydroxypropylated starches showed higher swelling power, solubility, solubility in dimethyl sulphoxide (DMSO) and paste clarity than their counterpart native starches. Light transmittance of hydroxypropylated starches did not change significantly during refrigerated storage while a substantial decrease in the same was observed for native starches. SEM pictures showed that the hydroxypropylated starch granules from all the potato cultivars differed in shape and size from the native starch granules, and showed the presence of slight fragmentation and a distinct groove in their central core region along the longitudinal axis. Hydroxypropylation treatment showed more pronounced effect on large size granules than small size granules. The extent of granule disruption was observed to be higher for hydroxypropylated starch gels that later developed numerous rod shaped or fuzzy clustered microfibrils with diameters ranging from 15 to 20 mm, after 30 days of refrigerated storage. The studies on the phase transitions associated with gelatinization of starches showed lower gelatinization parameters ðT o ; T p ; T c ; and DH gel Þ among the hydroxypropylated starches in which Kufri Jyoti and Kufri Sindhuri starches were the most affected. Hydroxypropylated potato starches exhibited higher peak G 0 ; G 00 and lower tan d during rheological measurements on the dynamic rheometer. Whereas the native starches did not possess freeze-thaw stability, upon hydroxypropylation there was a pronounced decrease in the tendency towards syneresis. q
Journal of Food Engineering, 2002
Effects of fatty acids (myristic and stearic acid) on the rheological properties of corn and pota... more Effects of fatty acids (myristic and stearic acid) on the rheological properties of corn and potato starch during heating and cooling were investigated using a Carri-Med CSL 2 dynamic rheometer. Potato starch showed a lower gelatinization temperature ðTG 0 Þ as compared to corn starch. Potato starch had a TG 0 of 61.2°C against 71.5°C for corn starch. The addition of both the fatty acids inhibited the swelling of the starch granules in both corn and potato starch and consequently, increased the TG 0 . The storage modulus ðG 0 Þ increased to a maximum and then dropped during heating of both the starches. Potato starch showed a higher peak G 0 value as compared to corn starch. Addition of stearic acid decreased the peak G 0 in corn starch and increased the same in potato starch, while the addition of myristic acid resulted in a decrease in peak G 0 in both the starches. The extent of breakdown in G 0 during heating was higher for potato starch as compared to corn starch which confirmed the more rigid structure of corn starch granules. During cooling, the G 0 values increased with decrease in temperature and with the addition of fatty acids. Corn starch showed higher peak loss tangent (tan d) values than potato starch during heating. Tan d values decreased during the cooling of corn and potato starch. Retrogradation (synersis) behaviour of both the starches heated in the presence of stearic and myristic acid during storage was also studied. The rate of synersis was more in potato starch than in corn starch. Synersis increased with the increase in storage duration and decreased with the addition of both the fatty acids. Ó
Food Hydrocolloids, 2003
Granulated cold water soluble (GCWS) starches were prepared from corn starch and starches separat... more Granulated cold water soluble (GCWS) starches were prepared from corn starch and starches separated from four potato cultivars using alcoholic-alkaline method. The morphological, thermal and rheological properties of GCWS corn and potato starches were studied. The amylose content of the GCWS starches from corn and potato starches were signi®cantly lower as compared to their counterparts native starches. GCWS potato starches showed higher cold water solubility than GCWS corn starch. Cold water solubility of GCWS starches prepared from different potato cultivars also differed signi®cantly. Native potato starch granules were larger in size (15±45 mm), smooth, oval and irregular or cuboidal shaped while native corn starch granules were smaller in size (5±18 mm), less smooth, rounded and angular shaped. Both corn and potato starches were distorted and indented during conversion to GCWS starches, however, this effect was more pronounced in potato starches than corn starch. The extent of distortion in GCWS starches differed signi®cantly in starches prepared from different potato cultivars. The potato cultivars having starch with large sized granules showed more granular distortion as compared in those having small sized granules during GCWS starch production. Native corn starch showed higher transition temperatures and lower enthalpy of gelatinization (DH gel ) than native potato starches. GCWS corn and potato starches did not show any gelatinization endotherm during heating between 20 and 100 8C. The rheological properties such as G 0 , G 00 , h 0 and Tan d of GCWS corn and potato starches also showed signi®cant variation, when subjected to frequency sweep testing. GCWS potato starches showed higher G 0 , G 00 , h 0 and lower Tan d than GCWS corn starch. The G 0 , G 00 , h 0 of the GCWS starches from both corn and potato increased and Tan d decreased with the increase in temperature. The turbidity of GCWS and native corn and potato starches increased during storage at 4 8C, however, the increase was less pronounced in GCWS starches. q
IEEE Transactions on Communications, 2009
As communication systems scale up in speed and bandwidth, the cost and power consumption of high-... more As communication systems scale up in speed and bandwidth, the cost and power consumption of high-precision (e.g., 8-12 bits) analog-to-digital conversion (ADC) becomes the limiting factor in modern transceiver architectures based on digital signal processing. In this work, we explore the impact of lowering the precision of the ADC on the performance of the communication link. Specifically, we evaluate the communication limits imposed by low-precision ADC (e.g., 1-3 bits) for transmission over the real discrete-time Additive White Gaussian Noise (AWGN) channel, under an average power constraint on the input. For an ADC with quantization bins (i.e., a precision of log 2 bits), we show that the input distribution need not have any more than +1 mass points to achieve the channel capacity. For 2-bin (1-bit) symmetric quantization, this result is tightened to show that binary antipodal signaling is optimum for any signalto-noise ratio (SNR). For multi-bit quantization, a dual formulation of the channel capacity problem is used to obtain tight upper bounds on the capacity. The cutting-plane algorithm is employed to compute the capacity numerically, and the results obtained are used to make the following encouraging observations : (a) up to a moderately high SNR of 20 dB, 2-3 bit quantization results in only 10-20% reduction of spectral efficiency compared to unquantized observations, (b) standard equiprobable pulse amplitude modulated input with quantizer thresholds set to implement maximum likelihood hard decisions is asymptotically optimum at high SNR, and works well at low to moderate SNRs as well.
Recent work has shown that, despite the minimal information provided by a binary proximity sensor... more Recent work has shown that, despite the minimal information provided by a binary proximity sensor, a network of such sensors can provide remarkably good target tracking performance. In this paper, we examine the performance of such a sensor network for tracking multiple targets. We begin with geometric arguments that address the problem of counting the number of distinct targets, given a snapshot of the sensor readings. We provide necessary and sufficient criteria for an accurate target count in a one-dimensional setting, and provide a greedy algorithm that determines the minimum number of targets that is consistent with the sensor readings. While these combinatorial arguments bring out the difficulty of target counting based on sensor readings at a given time, they leave open the possibility of accurate counting and tracking by exploiting the evolution of the sensor readings across time. To this end, we develop a particle filtering algorithm based on a cost function that penalizes changes in velocity. An extensive set of simulations, as well as experiments with passive infrared sensors, are reported. We conclude that, despite the combinatorial complexity of target counting, probabilistic approaches based on fairly generic models for the trajectories yield respectable tracking performance.
Computing Research Repository, 2008
We investigate the limits of communication over the discrete-time Additive White Gaussian Noise (... more We investigate the limits of communication over the discrete-time Additive White Gaussian Noise (AWGN) channel, when the channel output is quantized using a small number of bits. We first provide a proof of our recent conjecture on the optimality of a discrete input distribution in this scenario. Specifically, we show that for any given output quantizer choice with K quantization bins (i.e., a precision of log 2 K bits), the input distribution, under an average power constraint, need not have any more than K + 1 mass points to achieve the channel capacity. The cutting-plane algorithm is employed to compute this capacity and to generate optimum input distributions. Numerical optimization over the choice of the quantizer is then performed (for 2-bit and 3-bit symmetric quantization), and the results we obtain show that the loss due to low-precision output quantization, which is small at low signal-to-noise ratio (SNR) as expected, can be quite acceptable even for moderate to high SNR values. For example, at SNRs up to 20 dB, 2-3 bit quantization achieves 80-90% of the capacity achievable using infinite-precision quantization. * J. Singh and U. Madhow are with the ECE Department, UC Santa Barbara, CA 93106, USA.
Clinical Therapeutics, 2002
Subsets of psychiatric patients gain excess body weight while receiving mood-stabilizing agents s... more Subsets of psychiatric patients gain excess body weight while receiving mood-stabilizing agents such as lithium carbonate or valproate sodium. Patients who gain excess weight may discontinue therapy, with severe consequences. Among the newer anticonvulsant agents, topiramate is a candidate agent for bipolar disorder and is associated with weight loss when used as adjunctive treatment. This open-label, nonrandomized, chart-review study assessed changes in body weight and body mass index (BMI) in patients receiving topiramate, lithium, or valproate. Data were extracted from the medical charts of patients admitted in 1999 and 2000 to a state psychiatric hospital with either schizophrenia, schizoaffective disorder, bipolar disorder, or other psychiatric diagnoses who were prescribed valproate, lithium, or topiramate and were reviewed for changes in body weight and BMI. The use of concomitant psychotropic medicines was recorded (eg, antipsychotic agents, antidepressant agents, other mood stabilizers such as gabapentin or carbamazepine). Continuous variables were analyzed using a factorial analysis of variance and the Student t test. Contingency statistics were used to analyze categorical variables. A total of 214 patients were included in the chart review (123 men, 91 women; mean age, 39.4 years). Significantly more women than men received topiramate (P = 0.004). Patients receiving either lithium or valproate gained a mean (SD) of 6.3 (9.0) kg and 6.4 (9.0) kg, respectively, whereas patients receiving topiramate lost a mean 1.2 (6.3) kg (F = 11.54, df = 2,198; P < 0.001). Lithium- or valproate-treated patients experienced an increase in BMI (mean, 2.1 [3.0] for both groups), whereas topiramate-treated patients experienced a reduction in BMI (mean, -0.5 [2.4]); this result was statistically significant (F = 11.40, df = 2,198; P < 0.001). Finally, lithium- or valproate-treated patients gained >8% of their baseline body weight (8.2% [11.5%] for lithium-treated patients and 8.5% [11.9%] for valproate-treated patients), whereas topiramate-treated patients lost 0.7% (7.2%) of their body weight (F = 9.93, df= 2,198; P < 0.001). Controlled studies for the efficacy of topiramate therapy in various psychiatric conditions are awaited. These data indicate that patients receiving topiramate experience body weight loss and a reduction in BMI. This advantage of topiramate may promote long-term adherence to treatment among psychiatric patients and possibly decrease the medical risks associated with obesity.
Harvard Review of Psychiatry, 1994
The autoimmune basis for schizophrenia has been investigated for the last 60 years. Although nume... more The autoimmune basis for schizophrenia has been investigated for the last 60 years. Although numerous immune abnormalities have been reported, the current literature is viewed with much skepticism because most of the studies have failed to control for extraneous factors that may have influenced the findings. Principally, antipsychotic medication, duration of illness, and current clinical state (acutely psychotic or remitted) may considerably alter immune response, as may other factors such as nutritional status, substance abuse, and concurrent medical illness. We review recent studies that employed current diagnostic criteria and modern immunologic techniques. (These studies were located by use of a Medline search on the terms schizophrenia and psychosis, cross-referenced with immune abnormalities, lymphokines, antibodies, lymphocytes, HLA, and medication, and by perusing the reference lists in the articles found through this search.) Immune abnormalities that have been replicated in studies of schizophrenic patients include increased prevalence of antinuclear antibodies, decreased production of interleukin-2, and increased serum concentrations of interleukin-2 receptor and interleukin-6. Given the current importance of autoimmunity as an etiologic mechanism in several branches of medicine, further studies are needed, especially those having a longitudinal design and including drug-naive patients.
Single-walled carbon nanotubes (CNT) are mechanically robust graphene cylinders with a high aspec... more Single-walled carbon nanotubes (CNT) are mechanically robust graphene cylinders with a high aspect ratio that are comprised of sp 2 -bonded carbon atoms and possessing highly regular structures with defined periodicity. CNT exhibit unique mechanochemical properties that can be exploited for the development of novel drug delivery platforms. We hypothesized that novel prototype nanostructures consisting of biologics, radionuclides, fluorochromes, and CNT could be synthesized and designed to target tumor cells. Methods: Tumor-targeting CNT constructs were synthesized from sidewall-functionalized, water-soluble CNT platforms by covalently attaching multiple copies of tumorspecific monoclonal antibodies, radiometal-ion chelates, and fluorescent probes. The constructs were characterized spectroscopically, chromatographically, and electrophoretically. The specific reactivity of these constructs was evaluated in vitro by flow cytometry and cell-based immunoreactivity assays and in vivo using biodistribution in a murine xenograft model of lymphoma. Results: A soluble, reactive CNT platform was used as the starting point to build multifunctional constructs with appended antibody, metal-ion chelate, and fluorescent chromophore moieties to effect specific targeting, to carry and deliver a radiometal-ion, and to report location, respectively. These nanoconstructs were found to be specifically reactive with the human cancer cells they were designed to target in vivo in a model of disseminated human lymphoma and in vitro by flow cytometry and cell-based immunoreactivity assays versus appropriate controls. Conclusion: The key achievement in these studies was the selective targeting of tumor in vitro and in vivo by the use of specific antibodies appended to a soluble, nanoscale CNT construct. The ability to specifically target tumor with prototype-radiolabeled or fluorescent-labeled, antibody-appended CNT constructs was encouraging and suggested further investigation of CNT as a novel delivery platform.
Journal of Clinical Psychiatry, 2005
Obesity is common in persons with schizophrenia. Besides its adverse health effects, obesity redu... more Obesity is common in persons with schizophrenia. Besides its adverse health effects, obesity reduces quality of life and contributes to the social stigma of schizophrenia. This 14-week, multicenter, open-label, rater-blinded, randomized study evaluated the effects of a group-based behavioral treatment (BT) for weight loss in overweight and obese stable patients with DSM-IV schizophrenia or schizoaffective disorder who had been switched from olanzapine to risperidone. Participants were randomly assigned to receive BT or usual clinical care (UC). BT included 20 sessions during which patients were taught to reduce caloric intake. In UC, patients were encouraged to lose weight but received no special advice about weight reduction. The primary outcome measure was change in body weight. Seventy-two patients were enrolled. The mean +/- SD weight loss at endpoint was significant in both groups (p < .05) and numerically greater in patients receiving BT than in those receiving UC (-2.0 +/- 3.79 and -1.1 +/- 3.11 kg, respectively). More patients in the BT group than in the UC group had lost > or = 5% of their body weight at endpoint (26.5% [9/34] and 10.8% [4/37], respectively; p = .082). A post hoc analysis of patients attending at least 1 BT session showed that significantly more patients in the BT than the UC group had lost > or = 5% of their body weight at endpoint (32.1% [9/28] vs. 10.8% [4/37], respectively, p = .038) and at week 14 (complete population; 40.9% [9/22] and 14.3% [4/28], respectively, p = .027). BT may be an effective method for weight reduction in patients with chronic psychotic illness.
Food Hydrocolloids, 2007
Effect of some common chemical modifications such as acetylation, hydroxypropylation and cross-li... more Effect of some common chemical modifications such as acetylation, hydroxypropylation and cross-linking on the physico-chemical, morphological, thermal and rheological properties of starches from different botanical sources have been reviewed. The distinguishing factors that affect the efficiency of modification are the starch source, amylose to amylopectin ratio, granule morphology, and type and concentration of the modifying reagent. The extent of alteration in the starch properties reflects the resistance or the susceptibility of a starch towards different chemical modifications. Modified starches with desirable properties and degree of substitution can be prepared by critically selecting a suitable modifying agent and a native starch source. r
Starch-starke, 2004
Corn starch and starches separated from different potato cultivars were acetylated to evaluate th... more Corn starch and starches separated from different potato cultivars were acetylated to evaluate the effect of plant source on the physicochemical, morphological, thermal, rheological, textural and retrogradation properties of the starches. Corn starch showed a lower degree of acetylation than potato starches under similar experimental conditions. The degree of acetylation for different potato starches also differed significantly. Morphological examination revealed that the granules of acetylated Kufri Chandermukhi and Kufri Sindhuri starches tended to appear as fused and less smooth than native starch granules. Acetylation of corn and potato starches decreased the transition temperatures and enthalpy of gelatinization and increased swelling power and light transmittance. However, the change in these was greater in the potato starches with higher percentage of small sized granules. Acetylated starches showed higher peak G',G'' and lower tan δ than their counterpart native starches during heating. Among the starches from different cultivars, the change in the rheological parameters after acetylation differed to a significant extent. The retrogradation was observed to be negligible in the acetylated cooked starch pastes. Results implied that the change in functional properties of starches with acetylation depends on source and granule morphology of native starch.
Food Chemistry, 2004
The physicochemical, morphological, thermal and rheological properties of acetylated corn and pot... more The physicochemical, morphological, thermal and rheological properties of acetylated corn and potato starches, prepared using acetic anhydride at different levels (412 g), were compared. Corn starch showed lower acetyl (%) and degree of substitution (DS) than ...
Food Chemistry, 2001
The starches separated from five different Indian potato cultivars (Kufri Chandermukhi, Kufri Bad... more The starches separated from five different Indian potato cultivars (Kufri Chandermukhi, Kufri Badshah, Kufri Jyoti, Kufri Sindhuri and S1) were investigated for morphological, thermal, rheological, turbidity and water-binding properties. The starch separated from all the five ...
Food Chemistry, 2003
Morphology, thermal and rheological properties of starches from maize mutants deficient in starch... more Morphology, thermal and rheological properties of starches from maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were studied and compared with the wild type. SSIII deficiency reduced granule size of the starches from 16.7 to ~11 μm (volume-weighted mean). Thermal analysis showed that SSIII deficiency decreased the enthalpy change of starch during gelatinization. Steady shear analysis showed that SSIII deficiency decreased the consistency coefficient and yield stress during steady shearing, while additional deficiency in granule-bound starch synthase (GBSS) increased these values. Dynamic oscillatory analysis showed that SSIII deficiency decreased G' at 90 oC during heating, and increased it when the paste was cooled to 25 oC at 40 Hz during a frequency sweep. Additional GBSS deficiency further decreased the G'. Structural and compositional basis responsible for these changes in physical properties of the starches are discussed. This short communication highlighted the relationship between SSIII and some physicochemical properties of maize starch.
Carbohydrate Polymers, 2004
Starches separated from four potato cultivars were hydroxypropylated and their physico-chemical, ... more Starches separated from four potato cultivars were hydroxypropylated and their physico-chemical, morphological, thermal and rheological properties were compared. The extent of hydroxypropylation measured as molar substitution differed significantly among the starches from different potato cultivars. Kufri Jyoti hydroxypropylated starch showed highest molar substitution, while Kufri Chandermukhi hydroxypropylated starch showed the lowest. The hydroxypropylated starches showed higher swelling power, solubility, solubility in dimethyl sulphoxide (DMSO) and paste clarity than their counterpart native starches. Light transmittance of hydroxypropylated starches did not change significantly during refrigerated storage while a substantial decrease in the same was observed for native starches. SEM pictures showed that the hydroxypropylated starch granules from all the potato cultivars differed in shape and size from the native starch granules, and showed the presence of slight fragmentation and a distinct groove in their central core region along the longitudinal axis. Hydroxypropylation treatment showed more pronounced effect on large size granules than small size granules. The extent of granule disruption was observed to be higher for hydroxypropylated starch gels that later developed numerous rod shaped or fuzzy clustered microfibrils with diameters ranging from 15 to 20 mm, after 30 days of refrigerated storage. The studies on the phase transitions associated with gelatinization of starches showed lower gelatinization parameters ðT o ; T p ; T c ; and DH gel Þ among the hydroxypropylated starches in which Kufri Jyoti and Kufri Sindhuri starches were the most affected. Hydroxypropylated potato starches exhibited higher peak G 0 ; G 00 and lower tan d during rheological measurements on the dynamic rheometer. Whereas the native starches did not possess freeze-thaw stability, upon hydroxypropylation there was a pronounced decrease in the tendency towards syneresis. q
Journal of Food Engineering, 2002
Effects of fatty acids (myristic and stearic acid) on the rheological properties of corn and pota... more Effects of fatty acids (myristic and stearic acid) on the rheological properties of corn and potato starch during heating and cooling were investigated using a Carri-Med CSL 2 dynamic rheometer. Potato starch showed a lower gelatinization temperature ðTG 0 Þ as compared to corn starch. Potato starch had a TG 0 of 61.2°C against 71.5°C for corn starch. The addition of both the fatty acids inhibited the swelling of the starch granules in both corn and potato starch and consequently, increased the TG 0 . The storage modulus ðG 0 Þ increased to a maximum and then dropped during heating of both the starches. Potato starch showed a higher peak G 0 value as compared to corn starch. Addition of stearic acid decreased the peak G 0 in corn starch and increased the same in potato starch, while the addition of myristic acid resulted in a decrease in peak G 0 in both the starches. The extent of breakdown in G 0 during heating was higher for potato starch as compared to corn starch which confirmed the more rigid structure of corn starch granules. During cooling, the G 0 values increased with decrease in temperature and with the addition of fatty acids. Corn starch showed higher peak loss tangent (tan d) values than potato starch during heating. Tan d values decreased during the cooling of corn and potato starch. Retrogradation (synersis) behaviour of both the starches heated in the presence of stearic and myristic acid during storage was also studied. The rate of synersis was more in potato starch than in corn starch. Synersis increased with the increase in storage duration and decreased with the addition of both the fatty acids. Ó
Food Hydrocolloids, 2003
Granulated cold water soluble (GCWS) starches were prepared from corn starch and starches separat... more Granulated cold water soluble (GCWS) starches were prepared from corn starch and starches separated from four potato cultivars using alcoholic-alkaline method. The morphological, thermal and rheological properties of GCWS corn and potato starches were studied. The amylose content of the GCWS starches from corn and potato starches were signi®cantly lower as compared to their counterparts native starches. GCWS potato starches showed higher cold water solubility than GCWS corn starch. Cold water solubility of GCWS starches prepared from different potato cultivars also differed signi®cantly. Native potato starch granules were larger in size (15±45 mm), smooth, oval and irregular or cuboidal shaped while native corn starch granules were smaller in size (5±18 mm), less smooth, rounded and angular shaped. Both corn and potato starches were distorted and indented during conversion to GCWS starches, however, this effect was more pronounced in potato starches than corn starch. The extent of distortion in GCWS starches differed signi®cantly in starches prepared from different potato cultivars. The potato cultivars having starch with large sized granules showed more granular distortion as compared in those having small sized granules during GCWS starch production. Native corn starch showed higher transition temperatures and lower enthalpy of gelatinization (DH gel ) than native potato starches. GCWS corn and potato starches did not show any gelatinization endotherm during heating between 20 and 100 8C. The rheological properties such as G 0 , G 00 , h 0 and Tan d of GCWS corn and potato starches also showed signi®cant variation, when subjected to frequency sweep testing. GCWS potato starches showed higher G 0 , G 00 , h 0 and lower Tan d than GCWS corn starch. The G 0 , G 00 , h 0 of the GCWS starches from both corn and potato increased and Tan d decreased with the increase in temperature. The turbidity of GCWS and native corn and potato starches increased during storage at 4 8C, however, the increase was less pronounced in GCWS starches. q
IEEE Transactions on Communications, 2009
As communication systems scale up in speed and bandwidth, the cost and power consumption of high-... more As communication systems scale up in speed and bandwidth, the cost and power consumption of high-precision (e.g., 8-12 bits) analog-to-digital conversion (ADC) becomes the limiting factor in modern transceiver architectures based on digital signal processing. In this work, we explore the impact of lowering the precision of the ADC on the performance of the communication link. Specifically, we evaluate the communication limits imposed by low-precision ADC (e.g., 1-3 bits) for transmission over the real discrete-time Additive White Gaussian Noise (AWGN) channel, under an average power constraint on the input. For an ADC with quantization bins (i.e., a precision of log 2 bits), we show that the input distribution need not have any more than +1 mass points to achieve the channel capacity. For 2-bin (1-bit) symmetric quantization, this result is tightened to show that binary antipodal signaling is optimum for any signalto-noise ratio (SNR). For multi-bit quantization, a dual formulation of the channel capacity problem is used to obtain tight upper bounds on the capacity. The cutting-plane algorithm is employed to compute the capacity numerically, and the results obtained are used to make the following encouraging observations : (a) up to a moderately high SNR of 20 dB, 2-3 bit quantization results in only 10-20% reduction of spectral efficiency compared to unquantized observations, (b) standard equiprobable pulse amplitude modulated input with quantizer thresholds set to implement maximum likelihood hard decisions is asymptotically optimum at high SNR, and works well at low to moderate SNRs as well.
Recent work has shown that, despite the minimal information provided by a binary proximity sensor... more Recent work has shown that, despite the minimal information provided by a binary proximity sensor, a network of such sensors can provide remarkably good target tracking performance. In this paper, we examine the performance of such a sensor network for tracking multiple targets. We begin with geometric arguments that address the problem of counting the number of distinct targets, given a snapshot of the sensor readings. We provide necessary and sufficient criteria for an accurate target count in a one-dimensional setting, and provide a greedy algorithm that determines the minimum number of targets that is consistent with the sensor readings. While these combinatorial arguments bring out the difficulty of target counting based on sensor readings at a given time, they leave open the possibility of accurate counting and tracking by exploiting the evolution of the sensor readings across time. To this end, we develop a particle filtering algorithm based on a cost function that penalizes changes in velocity. An extensive set of simulations, as well as experiments with passive infrared sensors, are reported. We conclude that, despite the combinatorial complexity of target counting, probabilistic approaches based on fairly generic models for the trajectories yield respectable tracking performance.
Computing Research Repository, 2008
We investigate the limits of communication over the discrete-time Additive White Gaussian Noise (... more We investigate the limits of communication over the discrete-time Additive White Gaussian Noise (AWGN) channel, when the channel output is quantized using a small number of bits. We first provide a proof of our recent conjecture on the optimality of a discrete input distribution in this scenario. Specifically, we show that for any given output quantizer choice with K quantization bins (i.e., a precision of log 2 K bits), the input distribution, under an average power constraint, need not have any more than K + 1 mass points to achieve the channel capacity. The cutting-plane algorithm is employed to compute this capacity and to generate optimum input distributions. Numerical optimization over the choice of the quantizer is then performed (for 2-bit and 3-bit symmetric quantization), and the results we obtain show that the loss due to low-precision output quantization, which is small at low signal-to-noise ratio (SNR) as expected, can be quite acceptable even for moderate to high SNR values. For example, at SNRs up to 20 dB, 2-3 bit quantization achieves 80-90% of the capacity achievable using infinite-precision quantization. * J. Singh and U. Madhow are with the ECE Department, UC Santa Barbara, CA 93106, USA.