Braddock Linsley - Academia.edu (original) (raw)

Papers by Braddock Linsley

Paleoceanography and paleoclimatology, Sep 1, 2022

Marine Isotope Stage 3 (MIS 3), considered a relatively warm transitional interglacial stage that... more Marine Isotope Stage 3 (MIS 3), considered a relatively warm transitional interglacial stage that lasted from 60 ka to the beginning of the Last Glacial Maximum (LGM; 26 ka), is characterized by highly variable climate, punctuated by repeated millennial-scale warming episodes, called Dansgaard-Oeschger events, during which the North Atlantic warmed 8°-15°C (Blunier et al., 1998). The extent and variability of continental ice sheets and global mean sea level (GMSL) during MIS 3 relative to the LGM and to the preceding interglacial (MIS 5), has been implicated in causing this climate variability (Siddall et al., 2008 and references therein) and remains controversial. Constraining MIS 3 GMSL is crucial for (a) evaluating how quickly ice sheets grew and sea level fell as global climate transitioned into the LGM (Dalton et al., 2019; Pico et al., 2017), (b) understanding ice sheet stability in the past, and (c) projecting future ice sheet melting because it precedes the LGM and is characterized by substantial climatic instability. It has proven difficult however, to constrain sea level during this interval (Pico et al., 2017; Siddall et al., 2008). Many studies have estimated global ice volume from foraminiferal δ 18 O either by using paleo-reconstructions from regions where foraminiferal δ 18 O is thought to be strongly correlated to ice volume (

Paleoceanography and Paleoclimatology, 2020

The Great Barrier Reef (GBR) is an internationally recognized and widely studied ecosystem, yet l... more The Great Barrier Reef (GBR) is an internationally recognized and widely studied ecosystem, yet little is known about its sea surface temperature (SST) evolution since the Last Glacial Maximum (LGM) (~20 kyr BP). Here, we present the first paleo‐application of Isopora coral‐derived SST calibrations to a suite of 25 previously published fossil Isopora from the central GBR spanning ~25–11 kyr BP. The resultant multicoral Sr/Ca‐ and δ18O‐derived SST anomaly (SSTA) histories are placed within the context of published relative sea level, reef sequence, and coralgal reef assemblage evolution. Our new calculations indicate SSTs were cooler on average by ~5–5.5°C at Noggin Pass (~17°S) and ~7–8°C at Hydrographer's Passage (~20°S) (Sr/Ca‐derived) during the LGM, in line with previous estimates (Felis et al., 2014, https://doi.org/10.1038/ncomms5102). We focus on contextualizing the Younger Dryas Chronozone (YDC, ~12.9–11.7 kyr BP), whose Southern Hemisphere expression, in particular in ...

Nature Reviews Earth & Environment, 2020

The South Pacific Convergence Zone (SPCZ) is a band of intense rainfall and deep atmospheric conv... more The South Pacific Convergence Zone (SPCZ) is a band of intense rainfall and deep atmospheric convection extending from the equator to the subtropical South Pacific. The variability in rainfall, tropical cyclone activity, and sea level due to displacement of the SPCZ affects South Pacific Island populations and surrounding ecosystems. In this Review, we synthesize recent advances in understanding of the SPCZ in regards to the physical mechanisms responsible for its location and orientation, interactions with the principal modes of tropical climate variability, regional and global impacts, and response to human-induced climate change. These advances begin to provide a coherent description of its character and variability on synoptic, intraseasonal, interannual, and longer timescales. However, further efforts are needed to better assess and quantify the impact of the SPCZ on regional and global weather and atmospheric circulation. While current-generation climate models capture some aspects of SPCZ behavior, significant biases and deficiencies remain that limit confidence in future projections. Both improved climate model skill and new methods for regional modelling may better constrain future SPCZ projections, aiding adaptation and planning among vulnerable South Pacific communities. KEY POINTS • The South Pacific Convergence Zone is a major region of low-level wind convergence, convection and rainfall extending from the equator towards the southeast in the South Pacific, having a large impact on Pacific Island communities. • The location and intensity of the SPCZ vary on timescales ranging from days to decades, as the SPCZ interacts with regional climate drivers such as the El Nino-Southern Oscillation. • Future changes in the SPCZ are uncertain, with climate models disagreeing on whether the SPCZ will become wetter or drier, highlighting the need to improve model reliability in this region.

In the South Pacific Convergence Zone (SPCZ), the variability in a sub-seasonally resolved microa... more In the South Pacific Convergence Zone (SPCZ), the variability in a sub-seasonally resolved microatoll Porites colony Sr/Ca record from Tonga and a previously published high-resolution record from Fiji are strongly influenced by sea surface temperature (SST) over the calibration period from 1981 to 2004 (R^2 = 0.67 - 0.68). However, the Sr/Ca-derived SST correlation to instrumental SST decreases back in time. The lower frequency secular trend (~1°C) and decadal-scale (~2 - 3°C) modes in Sr/Ca-derived SST are almost two times larger than that observed in instrumental SST. The coral Sr/Ca records suggest that local effects on SST generate larger amplitude variability than gridded SST products indicate. Reconstructed d18O of seawater (d18Osw) at these sites correlate with instrumental sea surface salinity (SSS; r = 0.64 - 0.67) but not local precipitation (r = -0.10 to - 0.22) demonstrating that the advection and mixing of different salinity water masses may be the predominant control o...

Interpillow limestones were recovered from numerous cores of Leg 82. Limestones from Core 562-1, ... more Interpillow limestones were recovered from numerous cores of Leg 82. Limestones from Core 562-1, south of the Hayes Fracture Zone, display small-scale cross laminations composed of planktonic foraminiferal tests alternating with micrite. In nonlaminated portions of the limestones, graded bedding is evident. Foraminiferal species identified from thin sections date the limestones of Core 562-1 as early middle Miocene, approximately 16 Ma. This age corresponds with that determined for the lowermost sediments recovered at Site 562, which lie within 9 m of the interpillow limestones. The presence of undisturbed structures in the upper limestones may be the result of sediment void-infilling between pillow basalts, as opposed to a post-depositional intrusion of basalts into the carbonate sediments. Thus, the basalts have a minimum age of 16 Ma.

Science, Jun 28, 2017

Observed increases in ocean heat content (OHC) and temperature are robust indicators of global wa... more Observed increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. We used high-resolution proxy records from sediment cores to extend these observations in the Pacific 10,000 years beyond the instrumental record. We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1 T 0.4°C and 1.5 T 0.4°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades. Although documented changes in global surface temperatures during the Holocene and Common era are relatively small, the concomitant changes in OHC are large.

The Indonesian Throughflow (ITF) is thought to influence thermohaline circulation dynamics and is... more The Indonesian Throughflow (ITF) is thought to influence thermohaline circulation dynamics and is important for understanding global climate and the marine ecosystem. The physical and chemical properties of North Pacific Intermediate Water (NPIW) and the underlying deep water incorporated into the ITF appear to be the result of climate-related preconditioning in the North and South Pacific. Thus, these high-latitude source waters play an important role in the Indo-Pacific oceanography. Here, we present the results of down-core faunal analyses of fossil ostracods (Crustacea) that we argue reflect NPIW variability in the central part of the Makassar Strait in the ITF over the past 15 k.y. The results show that the warm-water and low-oxygen–water fauna, and species diversity, rapidly increased at ca. 12 ka, reaching maxima during the Younger Dryas (YD). We interpret the faunal change and the diversity maximum at ca. 12 ka as a response to the stagnation of intermediate water due to the...

Core top samples from Atlantic (Little Bahama Banks (LBB)) and Pacific (Hawaii and Indonesia) dep... more Core top samples from Atlantic (Little Bahama Banks (LBB)) and Pacific (Hawaii and Indonesia) depth transects have been analyzed in order to assess the influence of bottom water temperature (BWT) and aragonite saturation levels on Mg/Ca and Sr/Ca ratios in the aragonitic benthic foraminifer Hoeglundina elegans. Both the Mg/Ca and Sr/Ca ratios in H. elegans tests show a general decrease with increasing water depth. Although at each site the decreasing trends are consistent with the in situ temperature profile, Mg/Ca and Sr/Ca ratios in LBB are substantially higher than in Indonesia and Hawaii at comparable water depths with a greater difference observed with increasing water depth. Because we find no significant difference between results obtained on "live" and "dead" specimens, we propose that these differences are due to primary effects on the metal uptake during test formation. Evaluation of the water column properties at each site suggests that in situ CO3 ion concentrations play an important role in determining the H. elegans Mg/Ca and Sr/Ca ratios. The CO3 ion effect is limited, however, only to aragonite saturation levels ([DeltaCO3]aragonite) below 15 µmol/kg. Above this level, temperature exerts a dominant effect. Accordingly, we propose that Mg/Ca and Sr/Ca in H. elegans tests can be used to reconstruct thermocline temperatures only in waters oversaturated with respect to the mineral aragonite using the following relationships: Mg/Ca = (0.034 ± 0.002)BWT + (0.96 ± 0.03) and Sr/Ca = (0.060 ± 0.002)BWT + (1.53 ± 0.03) (for [DeltaCO3]aragonite > 15 µmol/kg). The standard error associated with these equations is about ±1.1°C. Reconstruction of deeper water temperatures is complicated because in undersaturated waters, changes in Mg/Ca and Sr/Ca ratios reflect a combination of changes in [CO3] and BWT. Overall, we find that Sr/Ca, rather than Mg/Ca, in H. elegans may be a more accurate proxy for reconstructing paleotemperatures.

INTRODUCTION AND OBJECTIVES: The tined lead for use with InterStim sacral neuromodulation (SNM) w... more INTRODUCTION AND OBJECTIVES: The tined lead for use with InterStim sacral neuromodulation (SNM) was introduced in 2002. However, little data on lead breakage has been published. In 2010 the manufacturer estimated a 1% rate of lead breakage and recommended removal from an incision over the sacrum (as opposed to from generator site). We previously described 5-year data of an 18% rate of lead breakage with risk factors of time since implantation and diabetes. The purpose of this review was to extend this data, and further define rate and risk factors for lead breakage. METHODS: We retrospectively reviewed lead explants from 2006 to 2018. Patients with non-tined lead, missing information or explant for infection or failed stage 1 were excluded. Clinical factors reviewed included age, BMI, gender, diabetes, time since implantation, history of prior revision and explant indication. Surgical techniques reviewed included cannulating the old lead with a straight stylet, and removal from an incision over the sacrum vs the generator site. Statistical analyses were performed as appropriate. RESULTS: 283 patients met study eligibility requirements. Patients were predominantly female (93%), non diabetic (85%), with mean age of 53 AE16, mean BMI 29.3AE7.8, and mean time since implantation of 2.8 AE2.1 years. Rate of lead breakage was 8.1%. The only significant difference between lead intact to lead breakage groups was time since implantation (p<0.001). On univariate analysis the following clinical factors were predictive of lead breakage: male gender, diabetes, time since implantation, history of fall/trauma, and surgeon. On multivariate, only gender (OR 8.2 95% CI 2.6-25.5) and time since implantation (OR 0.675 95% CI 0.555-0.821) remained significant. There was a 67% increased risk of lead breakage if time since implant was 4.5 versuss 2.2 years and an 8.2 times higher risk of lead breakage in males. Surgical technique used for lead removal was not significant. CONCLUSIONS: Overall rate of lead breakage was higher than estimated by the manufacturer, with the strongest predictor of lead breakage being the time interval since implantation. Interestingly, in all cases of lead breakage an incision over the sacrum had been made and this was not a protective factor. These findings are valuable for patient counseling prior to SNM revision.

Background: Salt is directly related to hypertension and cardiovascular disease associated with i... more Background: Salt is directly related to hypertension and cardiovascular disease associated with it. As obesity facilitates the effect of salt, a quantification of obese salt intake is necessary. Methods: Our patients numbering 56 have been recruited in the consultation of the obesity unit. Patients were given a questionnaire about their knowledge concerning salt. Natriuresis of 24 h was quantified. The average amount of sodium consumed per day from foods was determined (SAL), the average amount of sodium consumed per day from table salt added to cooking and seasoning (SAC) and the average total amount of sodium consumed per day (STOQ). Results: The mean age of our patients was 44.31 ± 12.8 years. The average BMI of our patients was 37.12 ± 5.9 kg/m 2. The average systolic blood pressure was 123.8 ± 14 mmHg and mean diastolic blood pressure was 76.45 ± 10.7 mmHg. The average amount of sodium consumed per day from food (SAL) was 1 915 ± 1038 mg. The average amount of sodium consumed per day from cooking salt (SAC) was 2487 ± 1663 mg. The total amount of sodium consumed per day (STOQ) was 4402 ± 1831 mg. This addition is equivalent to 11 ± 4.6 g of salt per day. The total sodium intake exceeded 2000 mg/day in 89.2% of patients. More than half (57%) of spontaneous sodium intake comes from salt added. The average natriuresis in our population is 158 ± 68 mmol/24 h, higher than the norm in 18% of cases. The majority (85%) of our patients have claimed that excess salt is bad to very bad for health. Conclusion: Our study showed the importance of salt consumption in obeses and especially table salt and yet the majority of our patients consider it to be harmful to health. It will be necessary to take into account the sodium intake when prescribing the diet.

A reconstruction of late Pleistocene surface water carbon isotopic (delta13C) variability is pres... more A reconstruction of late Pleistocene surface water carbon isotopic (delta13C) variability is presented from Ocean Drilling Program (ODP) site 769 in the Sulu Sea in the western tropical Pacific. The Sulu Sea is a shallowly silled back arc basin with a maximum sill depth of 420 m. Site 769 was drilled on a bathymetric high in 3643 m of water and has average late Pleistocene sedimentation rates of 8.5 cm/kyr. The oxygen isotope record (delta18O) of Globigerinoides ruber at site 769 shows a strong correlation with the SPECMAP stacked delta18O record, attesting to the continuity of sediment archive at the site. Surface delta13C displays consistent glacial-interglacial variability which averages ~0.9 per mil and has varied from 0.75 to 1.1 per mil over the last 800 kyr. Comparison to surface water delta13C records in the South China Sea and western tropical Pacific suggests that the glacial-interglacial surface delta13C variability is regional in scale. Planktonic delta13C data from ODP site 677 in the eastern Pacific is also coherent with the site 769. Additionally, we have found that the site 769 surface delta13C record is coherent at periods of 100 and 41 kyr with deepwater delta13C records from the Pacific. The highest correlation occurs with the deep eastern Pacific, where benthic delta13C data from cores RC13-110 and ODP site 677 closely match the Sulu Sea surface water record. We evaluate several possible controls of surface water delta13C in the Sulu Sea that may explain the coherent timing with Pacific deepwater delta13C records. These include variations in terrestrial organic matter flux to the basin, the upwelling of subsurface water and productivity changes, and the influx of western Pacific intermediate water to the Sulu Sea. Our preferred explanation involves a region of upper intermediate water upwelling in the far western Pacific which has been shown to outgas CO2 from subsurface waters into surface waters. Upwelling also occurs in the area of Panama Basin site 677. These equatorial upwelling zones cou [...]

Evidence from geologic archives suggests that there were large changes in the tropical hydrologic... more Evidence from geologic archives suggests that there were large changes in the tropical hydrologic cycle associated with the two prominent northern hemisphere deglacial cooling events, Heinrich Stadial 1 (HS1; ~19 to 15 kyr BP; kyr BP = 1000 yr before present) and the Younger Dryas (~12.9 to 11.7 kyr BP). These hydrologic shifts have been alternatively attributed to high and low latitude origin. Here, we present a new record of hydrologic variability based on planktic foraminifera-derived d18O of seawater (d18Osw) estimates from a sediment core from the tropical Eastern Indian Ocean, and using 12 additional d18Osw records, construct a single record of the dominant mode of tropical Eastern Equatorial Pacific and Indo-Pacific Warm Pool (IPWP) hydrologic variability. We show that deglacial hydrologic shifts parallel variations in the reconstructed interhemispheric temperature gradient, suggesting a strong response to variations in the Atlantic Meridional Overturning Circulation and the attendant heat redistribution. A transient model simulation of the last deglaciation suggests that hydrologic changes, including a southward shift in the Intertropical Convergence Zone (ITCZ) which likely occurred during these northern hemisphere cold events, coupled with oceanic advection and mixing, resulted in increased salinity in the Indonesian region of the IPWP and the eastern tropical Pacific, which is recorded by the d18Osw proxy. Based on our observations and modeling results we suggest the interhemispheric temperature gradient directly controls the tropical hydrologic cycle on these time scales, which in turn mediates poleward atmospheric heat transport.

Paleoceanography and paleoclimatology, Sep 1, 2022

Marine Isotope Stage 3 (MIS 3), considered a relatively warm transitional interglacial stage that... more Marine Isotope Stage 3 (MIS 3), considered a relatively warm transitional interglacial stage that lasted from 60 ka to the beginning of the Last Glacial Maximum (LGM; 26 ka), is characterized by highly variable climate, punctuated by repeated millennial-scale warming episodes, called Dansgaard-Oeschger events, during which the North Atlantic warmed 8°-15°C (Blunier et al., 1998). The extent and variability of continental ice sheets and global mean sea level (GMSL) during MIS 3 relative to the LGM and to the preceding interglacial (MIS 5), has been implicated in causing this climate variability (Siddall et al., 2008 and references therein) and remains controversial. Constraining MIS 3 GMSL is crucial for (a) evaluating how quickly ice sheets grew and sea level fell as global climate transitioned into the LGM (Dalton et al., 2019; Pico et al., 2017), (b) understanding ice sheet stability in the past, and (c) projecting future ice sheet melting because it precedes the LGM and is characterized by substantial climatic instability. It has proven difficult however, to constrain sea level during this interval (Pico et al., 2017; Siddall et al., 2008). Many studies have estimated global ice volume from foraminiferal δ 18 O either by using paleo-reconstructions from regions where foraminiferal δ 18 O is thought to be strongly correlated to ice volume (

Paleoceanography and Paleoclimatology, 2020

The Great Barrier Reef (GBR) is an internationally recognized and widely studied ecosystem, yet l... more The Great Barrier Reef (GBR) is an internationally recognized and widely studied ecosystem, yet little is known about its sea surface temperature (SST) evolution since the Last Glacial Maximum (LGM) (~20 kyr BP). Here, we present the first paleo‐application of Isopora coral‐derived SST calibrations to a suite of 25 previously published fossil Isopora from the central GBR spanning ~25–11 kyr BP. The resultant multicoral Sr/Ca‐ and δ18O‐derived SST anomaly (SSTA) histories are placed within the context of published relative sea level, reef sequence, and coralgal reef assemblage evolution. Our new calculations indicate SSTs were cooler on average by ~5–5.5°C at Noggin Pass (~17°S) and ~7–8°C at Hydrographer's Passage (~20°S) (Sr/Ca‐derived) during the LGM, in line with previous estimates (Felis et al., 2014, https://doi.org/10.1038/ncomms5102). We focus on contextualizing the Younger Dryas Chronozone (YDC, ~12.9–11.7 kyr BP), whose Southern Hemisphere expression, in particular in ...

Nature Reviews Earth & Environment, 2020

The South Pacific Convergence Zone (SPCZ) is a band of intense rainfall and deep atmospheric conv... more The South Pacific Convergence Zone (SPCZ) is a band of intense rainfall and deep atmospheric convection extending from the equator to the subtropical South Pacific. The variability in rainfall, tropical cyclone activity, and sea level due to displacement of the SPCZ affects South Pacific Island populations and surrounding ecosystems. In this Review, we synthesize recent advances in understanding of the SPCZ in regards to the physical mechanisms responsible for its location and orientation, interactions with the principal modes of tropical climate variability, regional and global impacts, and response to human-induced climate change. These advances begin to provide a coherent description of its character and variability on synoptic, intraseasonal, interannual, and longer timescales. However, further efforts are needed to better assess and quantify the impact of the SPCZ on regional and global weather and atmospheric circulation. While current-generation climate models capture some aspects of SPCZ behavior, significant biases and deficiencies remain that limit confidence in future projections. Both improved climate model skill and new methods for regional modelling may better constrain future SPCZ projections, aiding adaptation and planning among vulnerable South Pacific communities. KEY POINTS • The South Pacific Convergence Zone is a major region of low-level wind convergence, convection and rainfall extending from the equator towards the southeast in the South Pacific, having a large impact on Pacific Island communities. • The location and intensity of the SPCZ vary on timescales ranging from days to decades, as the SPCZ interacts with regional climate drivers such as the El Nino-Southern Oscillation. • Future changes in the SPCZ are uncertain, with climate models disagreeing on whether the SPCZ will become wetter or drier, highlighting the need to improve model reliability in this region.

In the South Pacific Convergence Zone (SPCZ), the variability in a sub-seasonally resolved microa... more In the South Pacific Convergence Zone (SPCZ), the variability in a sub-seasonally resolved microatoll Porites colony Sr/Ca record from Tonga and a previously published high-resolution record from Fiji are strongly influenced by sea surface temperature (SST) over the calibration period from 1981 to 2004 (R^2 = 0.67 - 0.68). However, the Sr/Ca-derived SST correlation to instrumental SST decreases back in time. The lower frequency secular trend (~1°C) and decadal-scale (~2 - 3°C) modes in Sr/Ca-derived SST are almost two times larger than that observed in instrumental SST. The coral Sr/Ca records suggest that local effects on SST generate larger amplitude variability than gridded SST products indicate. Reconstructed d18O of seawater (d18Osw) at these sites correlate with instrumental sea surface salinity (SSS; r = 0.64 - 0.67) but not local precipitation (r = -0.10 to - 0.22) demonstrating that the advection and mixing of different salinity water masses may be the predominant control o...

Interpillow limestones were recovered from numerous cores of Leg 82. Limestones from Core 562-1, ... more Interpillow limestones were recovered from numerous cores of Leg 82. Limestones from Core 562-1, south of the Hayes Fracture Zone, display small-scale cross laminations composed of planktonic foraminiferal tests alternating with micrite. In nonlaminated portions of the limestones, graded bedding is evident. Foraminiferal species identified from thin sections date the limestones of Core 562-1 as early middle Miocene, approximately 16 Ma. This age corresponds with that determined for the lowermost sediments recovered at Site 562, which lie within 9 m of the interpillow limestones. The presence of undisturbed structures in the upper limestones may be the result of sediment void-infilling between pillow basalts, as opposed to a post-depositional intrusion of basalts into the carbonate sediments. Thus, the basalts have a minimum age of 16 Ma.

Science, Jun 28, 2017

Observed increases in ocean heat content (OHC) and temperature are robust indicators of global wa... more Observed increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. We used high-resolution proxy records from sediment cores to extend these observations in the Pacific 10,000 years beyond the instrumental record. We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1 T 0.4°C and 1.5 T 0.4°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades. Although documented changes in global surface temperatures during the Holocene and Common era are relatively small, the concomitant changes in OHC are large.

The Indonesian Throughflow (ITF) is thought to influence thermohaline circulation dynamics and is... more The Indonesian Throughflow (ITF) is thought to influence thermohaline circulation dynamics and is important for understanding global climate and the marine ecosystem. The physical and chemical properties of North Pacific Intermediate Water (NPIW) and the underlying deep water incorporated into the ITF appear to be the result of climate-related preconditioning in the North and South Pacific. Thus, these high-latitude source waters play an important role in the Indo-Pacific oceanography. Here, we present the results of down-core faunal analyses of fossil ostracods (Crustacea) that we argue reflect NPIW variability in the central part of the Makassar Strait in the ITF over the past 15 k.y. The results show that the warm-water and low-oxygen–water fauna, and species diversity, rapidly increased at ca. 12 ka, reaching maxima during the Younger Dryas (YD). We interpret the faunal change and the diversity maximum at ca. 12 ka as a response to the stagnation of intermediate water due to the...

Core top samples from Atlantic (Little Bahama Banks (LBB)) and Pacific (Hawaii and Indonesia) dep... more Core top samples from Atlantic (Little Bahama Banks (LBB)) and Pacific (Hawaii and Indonesia) depth transects have been analyzed in order to assess the influence of bottom water temperature (BWT) and aragonite saturation levels on Mg/Ca and Sr/Ca ratios in the aragonitic benthic foraminifer Hoeglundina elegans. Both the Mg/Ca and Sr/Ca ratios in H. elegans tests show a general decrease with increasing water depth. Although at each site the decreasing trends are consistent with the in situ temperature profile, Mg/Ca and Sr/Ca ratios in LBB are substantially higher than in Indonesia and Hawaii at comparable water depths with a greater difference observed with increasing water depth. Because we find no significant difference between results obtained on "live" and "dead" specimens, we propose that these differences are due to primary effects on the metal uptake during test formation. Evaluation of the water column properties at each site suggests that in situ CO3 ion concentrations play an important role in determining the H. elegans Mg/Ca and Sr/Ca ratios. The CO3 ion effect is limited, however, only to aragonite saturation levels ([DeltaCO3]aragonite) below 15 µmol/kg. Above this level, temperature exerts a dominant effect. Accordingly, we propose that Mg/Ca and Sr/Ca in H. elegans tests can be used to reconstruct thermocline temperatures only in waters oversaturated with respect to the mineral aragonite using the following relationships: Mg/Ca = (0.034 ± 0.002)BWT + (0.96 ± 0.03) and Sr/Ca = (0.060 ± 0.002)BWT + (1.53 ± 0.03) (for [DeltaCO3]aragonite > 15 µmol/kg). The standard error associated with these equations is about ±1.1°C. Reconstruction of deeper water temperatures is complicated because in undersaturated waters, changes in Mg/Ca and Sr/Ca ratios reflect a combination of changes in [CO3] and BWT. Overall, we find that Sr/Ca, rather than Mg/Ca, in H. elegans may be a more accurate proxy for reconstructing paleotemperatures.

INTRODUCTION AND OBJECTIVES: The tined lead for use with InterStim sacral neuromodulation (SNM) w... more INTRODUCTION AND OBJECTIVES: The tined lead for use with InterStim sacral neuromodulation (SNM) was introduced in 2002. However, little data on lead breakage has been published. In 2010 the manufacturer estimated a 1% rate of lead breakage and recommended removal from an incision over the sacrum (as opposed to from generator site). We previously described 5-year data of an 18% rate of lead breakage with risk factors of time since implantation and diabetes. The purpose of this review was to extend this data, and further define rate and risk factors for lead breakage. METHODS: We retrospectively reviewed lead explants from 2006 to 2018. Patients with non-tined lead, missing information or explant for infection or failed stage 1 were excluded. Clinical factors reviewed included age, BMI, gender, diabetes, time since implantation, history of prior revision and explant indication. Surgical techniques reviewed included cannulating the old lead with a straight stylet, and removal from an incision over the sacrum vs the generator site. Statistical analyses were performed as appropriate. RESULTS: 283 patients met study eligibility requirements. Patients were predominantly female (93%), non diabetic (85%), with mean age of 53 AE16, mean BMI 29.3AE7.8, and mean time since implantation of 2.8 AE2.1 years. Rate of lead breakage was 8.1%. The only significant difference between lead intact to lead breakage groups was time since implantation (p<0.001). On univariate analysis the following clinical factors were predictive of lead breakage: male gender, diabetes, time since implantation, history of fall/trauma, and surgeon. On multivariate, only gender (OR 8.2 95% CI 2.6-25.5) and time since implantation (OR 0.675 95% CI 0.555-0.821) remained significant. There was a 67% increased risk of lead breakage if time since implant was 4.5 versuss 2.2 years and an 8.2 times higher risk of lead breakage in males. Surgical technique used for lead removal was not significant. CONCLUSIONS: Overall rate of lead breakage was higher than estimated by the manufacturer, with the strongest predictor of lead breakage being the time interval since implantation. Interestingly, in all cases of lead breakage an incision over the sacrum had been made and this was not a protective factor. These findings are valuable for patient counseling prior to SNM revision.

Background: Salt is directly related to hypertension and cardiovascular disease associated with i... more Background: Salt is directly related to hypertension and cardiovascular disease associated with it. As obesity facilitates the effect of salt, a quantification of obese salt intake is necessary. Methods: Our patients numbering 56 have been recruited in the consultation of the obesity unit. Patients were given a questionnaire about their knowledge concerning salt. Natriuresis of 24 h was quantified. The average amount of sodium consumed per day from foods was determined (SAL), the average amount of sodium consumed per day from table salt added to cooking and seasoning (SAC) and the average total amount of sodium consumed per day (STOQ). Results: The mean age of our patients was 44.31 ± 12.8 years. The average BMI of our patients was 37.12 ± 5.9 kg/m 2. The average systolic blood pressure was 123.8 ± 14 mmHg and mean diastolic blood pressure was 76.45 ± 10.7 mmHg. The average amount of sodium consumed per day from food (SAL) was 1 915 ± 1038 mg. The average amount of sodium consumed per day from cooking salt (SAC) was 2487 ± 1663 mg. The total amount of sodium consumed per day (STOQ) was 4402 ± 1831 mg. This addition is equivalent to 11 ± 4.6 g of salt per day. The total sodium intake exceeded 2000 mg/day in 89.2% of patients. More than half (57%) of spontaneous sodium intake comes from salt added. The average natriuresis in our population is 158 ± 68 mmol/24 h, higher than the norm in 18% of cases. The majority (85%) of our patients have claimed that excess salt is bad to very bad for health. Conclusion: Our study showed the importance of salt consumption in obeses and especially table salt and yet the majority of our patients consider it to be harmful to health. It will be necessary to take into account the sodium intake when prescribing the diet.

A reconstruction of late Pleistocene surface water carbon isotopic (delta13C) variability is pres... more A reconstruction of late Pleistocene surface water carbon isotopic (delta13C) variability is presented from Ocean Drilling Program (ODP) site 769 in the Sulu Sea in the western tropical Pacific. The Sulu Sea is a shallowly silled back arc basin with a maximum sill depth of 420 m. Site 769 was drilled on a bathymetric high in 3643 m of water and has average late Pleistocene sedimentation rates of 8.5 cm/kyr. The oxygen isotope record (delta18O) of Globigerinoides ruber at site 769 shows a strong correlation with the SPECMAP stacked delta18O record, attesting to the continuity of sediment archive at the site. Surface delta13C displays consistent glacial-interglacial variability which averages ~0.9 per mil and has varied from 0.75 to 1.1 per mil over the last 800 kyr. Comparison to surface water delta13C records in the South China Sea and western tropical Pacific suggests that the glacial-interglacial surface delta13C variability is regional in scale. Planktonic delta13C data from ODP site 677 in the eastern Pacific is also coherent with the site 769. Additionally, we have found that the site 769 surface delta13C record is coherent at periods of 100 and 41 kyr with deepwater delta13C records from the Pacific. The highest correlation occurs with the deep eastern Pacific, where benthic delta13C data from cores RC13-110 and ODP site 677 closely match the Sulu Sea surface water record. We evaluate several possible controls of surface water delta13C in the Sulu Sea that may explain the coherent timing with Pacific deepwater delta13C records. These include variations in terrestrial organic matter flux to the basin, the upwelling of subsurface water and productivity changes, and the influx of western Pacific intermediate water to the Sulu Sea. Our preferred explanation involves a region of upper intermediate water upwelling in the far western Pacific which has been shown to outgas CO2 from subsurface waters into surface waters. Upwelling also occurs in the area of Panama Basin site 677. These equatorial upwelling zones cou [...]

Evidence from geologic archives suggests that there were large changes in the tropical hydrologic... more Evidence from geologic archives suggests that there were large changes in the tropical hydrologic cycle associated with the two prominent northern hemisphere deglacial cooling events, Heinrich Stadial 1 (HS1; ~19 to 15 kyr BP; kyr BP = 1000 yr before present) and the Younger Dryas (~12.9 to 11.7 kyr BP). These hydrologic shifts have been alternatively attributed to high and low latitude origin. Here, we present a new record of hydrologic variability based on planktic foraminifera-derived d18O of seawater (d18Osw) estimates from a sediment core from the tropical Eastern Indian Ocean, and using 12 additional d18Osw records, construct a single record of the dominant mode of tropical Eastern Equatorial Pacific and Indo-Pacific Warm Pool (IPWP) hydrologic variability. We show that deglacial hydrologic shifts parallel variations in the reconstructed interhemispheric temperature gradient, suggesting a strong response to variations in the Atlantic Meridional Overturning Circulation and the attendant heat redistribution. A transient model simulation of the last deglaciation suggests that hydrologic changes, including a southward shift in the Intertropical Convergence Zone (ITCZ) which likely occurred during these northern hemisphere cold events, coupled with oceanic advection and mixing, resulted in increased salinity in the Indonesian region of the IPWP and the eastern tropical Pacific, which is recorded by the d18Osw proxy. Based on our observations and modeling results we suggest the interhemispheric temperature gradient directly controls the tropical hydrologic cycle on these time scales, which in turn mediates poleward atmospheric heat transport.