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The oncologic equivalence of laparoscopic distal pancreatectomy (LDP) to open pancreatectomy (ODP) for ductal adenocarcinoma (DAC) is not established. The National Cancer Data Base was used to compare perioperative outcomes following LDP and ODP for DAC between 2010 and 2011. One hundred forty-five patients underwent LDP; 625 underwent ODP. Compared with ODP, patients undergoing LDP were older (68 ± 10.1 vs 66 ± 10.5 years, P = .027), more likely treated in academic centers (70% vs 59%, P = .01), and had shorter hospital stays (6.8 ± 4.6 vs 8.9 ± 7.5 days, P < .001). Demographic data, lymph node count, 30-day unplanned readmission, and 30-day mortality were identical between groups. Multivariable regression identified a lower probability of prolonged length of stay with LDP (odds ratio .51, 95% confidence interval .327 to .785, P = .0023). There was no association between surgical approach and node count, readmission, or mortality. LDP for DAC provides shorter postoperative lengths of stay and rates of readmission and 30-day mortality similar to OPD without compromising perioperative oncologic outcomes.

The movements of some long-distance migrants are driven by innate compass headings that they follow on their first migrations (e.g., some birds and insects), while the movements of other first-time migrants are learned by following more experienced conspecifics (e.g., baleen whales). However, the overall roles of innate, learned, and social behaviors in driving migration goals in many taxa are poorly understood. To look for evidence of whether migration routes are innate or learned for sea turtles, here for 42 sites around the world we compare the migration routes of >400 satellite-tracked adults of multiple species of sea turtle with ∼45 000 Lagrangian hatchling turtle drift scenarios. In so doing, we show that the migration routes of adult turtles are strongly related to hatchling drift patterns, implying that adult migration goals are learned through their past experiences dispersing with ocean currents. The diverse migration destinations of adults consistently reflected the diversity in sites they would have encountered as drifting hatchlings. Our findings reveal how a simple mechanism, juvenile passive drift, can explain the ontogeny of some of the longest migrations in the animal kingdom and ensure that adults find suitable foraging sites.

From 1979 to 2022, the summer monsoon precipitation has increased by a substantial 40% over Northwest India compared to the 1980s. This wetting trend aligns with the future projections of the Coupled Model Intercomparison Project 6 (CMIP6). The observationally constrained reanalysis data indicates that significant sea surface warming in the western equatorial Indian Ocean and the Arabian Sea is likely driving this increase in rainfall by enhancing the cross‐equatorial monsoonal flow and associated evaporation. We demonstrate that the strengthening of the cross‐equatorial monsoon winds is due to the rapid warming of the Indian Ocean and the enhanced Pacific Ocean trade winds, which result from the poleward shift and expansion of the Hadley cell. These strengthened winds boost the latent heat flux (evaporation), leading to increased moisture transport to Northwest India. Plain Language Summary From 1979 to 2022, the summer monsoon precipitation has increased by a substantial 40% over Northwest India compared to the 1980s. The analysis suggests that a noticeable warming of the sea surface in the western equatorial Indian Ocean and the Arabian Sea could be causing this increase in rainfall. This warming strengthens the winds crossing the equator in the Indian Ocean and increases evaporation. The study also shows that the monsoon winds are strengthened due to the rapid warming of the Indian Ocean and the enhanced Pacific Ocean trade winds. These stronger winds cause more evaporation, which means more moisture is carried from the ocean to the land, leading to increased monsoon rainfall. Key Points Large increase in summer monsoon precipitation over Northwest India The strengthening of the monsoon winds and the Indian Ocean warming drives increasing evaporation Poleward shift and expansion of high‐pressure belts and the Indian Ocean warming are responsible for the strengthening of winds

Global hydrographic and air–sea freshwater flux datasets are used to investigate ocean salinity changes over 1950–2010 in relation to surface freshwater flux. On multi-decadal timescales, surface salinity increases (decreases) in evaporation (precipitation) dominated regions, the Atlantic–Pacific salinity contrast increases, and the upper thermocline salinity maximum increases while the salinity minimum of intermediate waters decreases. Potential trends in E–P are examined for 1950–2010 (using two reanalyses) and 1979–2010 (using four reanalyses and two blended products). Large differences in the 1950–2010 E–P trend patterns are evident in several regions, particularly the North Atlantic. For 1979–2010 some coherency in the spatial change patterns is evident but there is still a large spread in trend magnitude and sign between the six E–P products. However, a robust pattern of increased E–P in the southern hemisphere subtropical gyres is seen in all products. There is also some evidence in the tropical Pacific for a link between the spatial change patterns of salinity and E–P associated with ENSO. The water cycle amplification rate over specific regions is subsequently inferred from the observed 3-D salinity change field using a salt conservation equation in variable isopycnal volumes, implicitly accounting for the migration of isopycnal surfaces. Inferred global changes of E–P over 1950–2010 amount to an increase of 1 ± 0.6 % in net evaporation across the subtropics and an increase of 4.2 ± 2 % in net precipitation across subpolar latitudes. Amplification rates are approximately doubled over 1979–2010, consistent with accelerated broad-scale warming but also coincident with much improved salinity sampling over the latter period.

Deep-water formation in the eastern Subpolar North Atlantic Ocean (eSPNA) and Nordic Seas is crucial for maintaining the lower limb of the Atlantic Meridional Overturning Circulation (AMOC), of consequence for global climate. However, it is still uncertain which processes determine the deep-water formation and how much Atlantic and Arctic waters respectively contribute to the lower limb. To address this, here we used Lagrangian trajectories to diagnose a global eddy-resolving ocean model that agrees well with recent observations highlighting the eSPNA as a primary source of the AMOC lower limb. Comprised of 72% Atlantic waters and 28% Arctic waters, the density and depth of the AMOC lower limb is critically dependent on Atlantic-Arctic mixing, primarily in the vicinity of Denmark Strait. In contrast, Atlantic waters gaining density through air-sea interaction along the eastern periphery of Nordic Seas and not entering the Arctic Ocean make a negligible contribution to the lower limb. The authors use a global eddy-resolving ocean model and show that the Atlantic-Arctic mixing is necessary for determining the density and depth of the Atlantic Meridional Overturning Circulation return flow.

Improvement of subseasonal to seasonal North Atlantic winter forecasting requires better prediction of the North Atlantic Oscillation (NAO), the dominant mode of variability in the Northern Hemisphere. Despite recent research demonstrating the importance of stratosphere‐troposphere coupling for NAO predictability, the driving mechanisms and implications are not fully understood. This study reveals that the October upper stratosphere is highly relevant to polar vortex development and predictability of winter NAO. We derive a simple index based on the strength of meridional wind in the upper stratospheric surf zone and find that anomalously poleward motion is associated with a significantly stronger polar vortex, which predicts the subsequent winter surface NAO with a correlation coefficient of r = 0.40. Plain Language Summary The North Atlantic Oscillation (NAO) is a large‐scale atmospheric system that significantly affects the weather and climate in the North Atlantic basin, especially in winter. Accurately forecasting the NAO 1–3 months ahead is challenging. However, on these timescales, more predictable factors like the stratosphere play a crucial role in modulating the NAO. The upper stratosphere plays a significant role in stratospheric dynamics, however it remains poorly understood and its potential to improve winter NAO predictions is largely untapped. Here, we create a simple index to measure the north‐south winds in the upper stratosphere during October and find that a positive index predicts a stronger winter polar vortex, leading to a more positive NAO. This results in warmer, wetter, and stormier conditions in northern Europe and the eastern US, and colder, drier conditions in southern Europe and Canada. Conversely, a negative index indicates a weaker winter polar vortex and an increased likelihood of sudden stratospheric warming events, which can often lead to extreme and prolonged cold conditions at the surface. Our findings highlight the importance of monitoring the upper stratosphere in October to improve winter NAO predictions and better understand stratosphere‐troposphere coupling. Key Points The meridional wind in the midlatitude upper stratosphere in October contains significant seasonal predictability for the winter NAO The strength of the meridional wind in this region also predicts changes in the occurrence of midwinter SSWs The winter surface impact of the October upper stratospheric wind occurs partly, but not entirely, via changes to the polar vortex

Background Borderline resectable pancreatic cancers infiltrate into adjacent vascular structures to an extent that makes an R0 resection unlikely when pancreatectomy is performed de novo. In a pilot study, Alliance for Clinical Trials in Oncology Trial A021101, the median survival of patients who received chemotherapy and radiation prior to anticipated pancreatectomy was 22 months, and 64% of operations achieved an R0 resection. However, the individual contributions of preoperative chemotherapy and radiation therapy to therapeutic outcome remain poorly defined. Methods In Alliance for Clinical Oncology Trial A021501, a recently activated randomized phase II trial, patients ( N  = 134) with a CT or MRI showing a biopsy-confirmed pancreatic ductal adenocarcinoma that meets centrally-reviewed anatomic criteria for borderline resectable disease will be randomized to receive either 8 cycles of modified FOLFIRINOX (oxaliplatin 85 mg/m 2 , irinotecan 180 mg/m 2 , leucovorin 400 mg/m 2 and infusional 5-fluorouracil 2400 mg/m 2 over 2 days for 4 cycles) or to 7 cycles of modified FOLFIRINOX followed by stereotactic body radiation therapy (33–40 Gy in 5 fractions). Patients without evidence of disease progression following preoperative therapy will undergo pancreatectomy and will subsequently receive 4 cycles of postoperative modified FOLFOX6 (oxaliplatin 85 mg/m 2 , leucovorin 400 mg/m 2 , bolus 5-fluorouracil 400 mg/m 2 , and infusional 5-fluorouracil 2400 mg/m 2 over 2 days for 4 cycles). The primary endpoint is the 18-month overall survival rate of patients enrolled into each of the two treatment arms. An interim analysis of the R0 resection rate within each arm will be conducted to assess treatment futility after accrual of 30 patients. Secondary endpoints include rates of margin-negative resection and event-free survival. The primary analysis will compare the 18-month overall survival rate of each arm to a historical control rate of 50%. The trial is activated nationwide and eligible to be opened for accrual at any National Clinical Trials Network cooperative group member site. Discussion This study will help define standard preoperative treatment regimens for borderline resectable pancreatic cancer and position the superior arm for further evaluation in future phase III trials. Trial registration ClinicalTrials.gov : NCT02839343 , registered July 14, 2016.

The North Atlantic and Europe experienced two extreme climate events in 2015: exceptionally cold ocean surface temperatures and a summer heat wave ranked in the top ten over the past 65 years. Here, we show that the cold ocean temperatures were the most extreme in the modern record over much of the mid-high latitude North-East Atlantic. Further, by considering surface heat loss, ocean heat content and wind driven upwelling we explain for the first time the genesis of this cold ocean anomaly. We find that it is primarily due to extreme ocean heat loss driven by atmospheric circulation changes in the preceding two winters combined with the re-emergence of cold ocean water masses. Furthermore, we reveal that a similar cold Atlantic anomaly was also present prior to the most extreme European heat waves since the 1980s indicating that it is a common factor in the development of these events. For the specific case of 2015, we show that the ocean anomaly is linked to a stationary position of the Jet Stream that favours the development of high surface temperatures over Central Europe during the heat wave. Our study calls for an urgent assessment of the impact of ocean drivers on major European summer temperature extremes in order to provide better advance warning measures of these high societal impact events.

Changes in the global water cycle critically impact environmental, agricultural, and energy systems relied upon by humanity (Jiménez Cisneros et al 2014 Climate Change 2014: Impacts, Adaptation, and Vulnerability (Cambridge: Cambridge University Press)). Understanding recent water cycle change is essential in constraining future projections. Warming-induced water cycle change is expected to amplify the pattern of sea surface salinity (Durack et al 2012 Science 336 455-8). A puzzle has, however, emerged. The surface salinity pattern has amplified by 5%-8% since the 1950s (Durack et al 2012 Science 336 455-8, Skliris et al 2014 Clim. Dyn. 43 709-36) while the water cycle is thought to have amplified at close to half that rate (Durack et al 2012 Science 336 455-8, Skliris et al 2016 Sci. Rep. 6 752). This discrepancy is also replicated in climate projections of the 21st century (Durack et al 2012 Science 336 455-8). Using targeted numerical ocean model experiments we find that, while surface water fluxes due to water cycle change and ice mass loss amplify the surface salinity pattern, ocean warming exerts a substantial influence. Warming increases near-surface stratification, inhibiting the decay of existing salinity contrasts and further amplifying surface salinity patterns. Observed ocean warming can explain approximately half of observed surface salinity pattern changes from 1957-2016 with ice mass loss playing a minor role. Water cycle change of 3.6% ± 2.1% per degree Celsius of surface air temperature change is sufficient to explain the remaining observed salinity pattern change.