A simple mechanism for the climatological midsummer drought along the Pacific coast of Central America

© ATMOSFERA, 2013. This article is posted here by permission of ATMOSFERA for personal use, not for redistribution. The definitive version was published in Atmósfera 26 (2013): 261-281.The global distribution, seasonal evolution, and underlying mechanisms for the climatological midsummer drought (MSD) are investigated using a suite of relatively high spatial and temporal resolution station observations and reanalysis data with particular focus on the Pacific coast of Central America and southern Mexico. Although the MSD of Central America stands out in terms of spatial scale and coherence, it is neither unique to the Greater Caribbean Region (GCR) nor necessarily the strongest MSD on Earth based on an objective analysis of several global precipitation data sets. A mechanism for the MSD is proposed that relates the latitudinal dependence of the two climatological precipitation maxima to the biannual crossing of the solar declination (SD), driving two peaks in convective instability and hence rainfall. In addition to this underlying local mechanism, a number of remote processes tend to peak during the apex of the MSD, including the North American monsoon, the Caribbean low-level jet, and the North Atlantic subtropical high, which may also act to suppress rainfall along the Pacific coast of Central America and generate interannual variability in the strength or timing of the MSD. However, our findings challenge the existing paradigm that the MSD owes its existence to a precipitation-suppressing mechanism. Rather, aided by the analysis of higher-temporal resolution precipitation records and considering variations in latitude, we suggest the MSD is essentially the result of one precipitation-enhancing mechanism occurring twice.The authors gratefully acknowledge funding from the NOAA Climate Program Office (CPO) Modeling, Analysis, Predictions, and Projections (MAPP) Program, under awards NA10OAR0110239 to the Woods Hole Oceanographic Institution, NA10OAR4310253 to the University of Maryland, and NA10OAR4310252 to Columbia University

NASA Tropical Rainfall Measurement Mission (TRMM): Effects of tropical rainfall on upper ocean dynamics, air-sea coupling and hydrologic cycle

This was a Tropical Rainfall Measurement Mission (TRMM) modeling, analysis and applications research project. Our broad scientific goals addressed three of the seven TRMM Priority Science Questions, specifically: What is the monthly average rainfall over the tropical ocean areas of about 10(exp 5) sq km, and how does this rain and its variability affect the structure and circulation of the tropical oceans? What is the relationship between precipitation and changes in the boundary conditions at the Earth's surface (e.g., sea surface temperature, soil properties, vegetation)? How can improved documentation of rainfall improve understanding of the hydrological cycle in the tropics

Observing the Galápagos–EUC interaction : insights and challenges

Author Posting. © American Meteorological Society, 2010. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 40 (2010): 2768–2777, doi:10.1175/2010JPO4461.1.Although sustained observations yield a description of the mean equatorial current system from the western Pacific to the eastern terminus of the Tropical Atmosphere Ocean (TAO) array, a comprehensive observational dataset suitable for describing the structure and pathways of the Equatorial Undercurrent (EUC) east of 95°W does not exist and therefore climate models are unconstrained in a region that plays a critical role in ocean–atmosphere coupling. Furthermore, ocean models suggest that the interaction between the EUC and the Galápagos Islands (92°W) has a striking effect on the basic state and coupled variability of the tropical Pacific. To this end, the authors interpret historical measurements beginning with those made in conjunction with the discovery of the Pacific EUC in the 1950s, analyze velocity measurements from an equatorial TAO mooring at 85°W, and analyze a new dataset from archived shipboard ADCP measurements. Together, the observations yield a possible composite description of the EUC structure and pathways in the eastern equatorial Pacific that may be useful for model validation and guiding future observation.Karnauskas acknowledges the WHOI Penzance Endowed Fund in Support of Assistant Scientists

Conditional Deletion of Dnaic1 in a Murine Model of Primary Ciliary Dyskinesia Causes Chronic Rhinosinusitis

Studies of primary ciliary dyskinesia (PCD) have been hampered by the lack of a suitable animal model because disruption of essential ciliary genes in mice results in a high incidence of lethal hydrocephalus. To develop a viable mouse model for long-term studies of PCD, we have generated a transgenic mouse line in which two conserved exons of the mouse intermediate dynein chain gene, Dnaic1, are flanked by loxP sites (Dnaic1flox/flox). Dnaic1 is the murine homolog of human DNAI1, which is mutated in approximately 10% of human PCD cases. These mice have been crossed with mice expressing a tamoxifen-inducible Cre recombinase (CreER). Treatment of adult Dnaic1flox/flox/CreER+/− mice with tamoxifen results in an almost complete deletion of Dnaic1 with no evidence of hydrocephalus. Treated animals have reduced levels of full-length Dnaic1 mRNA, and electron micrographs of cilia demonstrate a loss of outer dynein arm structures. In treated Dnaic1flox/flox/CreER+/− animals, mucociliary clearance (MCC) was reduced over time. After approximately 3 months, no MCC was observed in the nasopharynx, whereas in the trachea, MCC was observed for up to 6 months, likely reflecting a difference in the turnover of ciliated cells in these tissues. All treated animals developed severe rhinosinusitis, demonstrating the importance of MCC to the health of the upper airways. However, no evidence of lung disease was observed up to 11 months after Dnaic1 deletion, suggesting that other mechanisms are able to compensate for the lack of MCC in the lower airways of mice. This model will be useful for the study of the pathogenesis and treatment of PCD

An Earth-system prediction initiative for the twenty-first century

International audienceSome scientists have proposed the Earth-System Prediction Initiative (EPI) at the 2007 GEO Summit in Cape Town, South Africa. EPI will draw upon coordination between international programs for Earth system observations, prediction, and warning, such as the WCRP, WWRP, GCOS, and hence contribute to GEO and the GEOSS. It will link with international organizations, such as the International Council for Science (ICSU), Intergovernmental Oceanographic Commission (IOC), UNEP, WMO, and World Health Organization (WHO). The proposed initiative will provide high-resolution climate models that capture the properties of regional high-impact weather events, such as tropical cyclones, heat wave, and sand and dust storms associated within multi-decadal climate projections of climate variability and change. Unprecedented international collaboration and goodwill are necessary for the success of EPI

Ecological and evolutionary consequences of alternative sex-change pathways in fish

Sequentially hermaphroditic fish change sex from male to female (protandry) or vice versa (protogyny), increasing their fitness by becoming highly fecund females or large dominant males, respectively. These life-history strategies present different social organizations and reproductive modes, from near-random mating in protandry, to aggregate- and harem-spawning in protogyny. Using a combination of theoretical and molecular approaches, we compared variance in reproductive success (V k*) and effective population sizes (N e) in several species of sex-changing fish. We observed that, regardless of the direction of sex change, individuals conform to the same overall strategy, producing more offspring and exhibiting greater V k* in the second sex. However, protogynous species show greater V k*, especially pronounced in haremic species, resulting in an overall reduction of N e compared to protandrous species. Collectively and independently, our results demonstrate that the direction of sex change is a pivotal variable in predicting demographic changes and resilience in sex-changing fish, many of which sustain highly valued and vulnerable fisheries worldwide

Sex- and age-related differences in the management and outcomes of chronic heart failure: an analysis of patients from the ESC HFA EORP Heart Failure Long-Term Registry

Aims: This study aimed to assess age- and sex-related differences in management and 1-year risk for all-cause mortality and hospitalization in chronic heart failure (HF) patients. Methods and results: Of 16 354 patients included in the European Society of Cardiology Heart Failure Long-Term Registry, 9428 chronic HF patients were analysed [median age: 66 years; 28.5% women; mean left ventricular ejection fraction (LVEF) 37%]. Rates of use of guideline-directed medical therapy (GDMT) were high (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, beta-blockers and mineralocorticoid receptor antagonists: 85.7%, 88.7% and 58.8%, respectively). Crude GDMT utilization rates were lower in women than in men (all differences: P\ua0 64 0.001), and GDMT use became lower with ageing in both sexes, at baseline and at 1-year follow-up. Sex was not an independent predictor of GDMT prescription; however, age >75 years was a significant predictor of GDMT underutilization. Rates of all-cause mortality were lower in women than in men (7.1% vs. 8.7%; P\ua0=\ua00.015), as were rates of all-cause hospitalization (21.9% vs. 27.3%; P\ua075 years. Conclusions: There was a decline in GDMT use with advanced age in both sexes. Sex was not an independent predictor of GDMT or adverse outcomes. However, age >75 years independently predicted lower GDMT use and higher all-cause mortality in patients with LVEF 6445%

Chelidonichthys lucerna. In: Sartor P., Mannini A., Carlucci R., Massaro E., Queirolo S., Sabatini A., Scarcella G.,

The maximum length reported in literature is 77.1 cm TL (Adriatic sea), the maximum weight 6.0 kg, reported in France. The maximum reported age is 15 years. In the Adriatic Sea, the size structure highlights two main cohorts . A relationship between size, depth and season was highlighted for centralnorthern Adriatic where juveniles concentrate in shallow coastal waters during summer, probably thanks to food abundance, in compliance with literature Von Bertalanffy growth function parameters showed that Chelidonichthys lucerna is a relatively fast-growing and moderately long-living species, like other triglids . Females seem to have a slightly faster growth rate than males and reach larger maximum size at the same age along Tuscany coast. It was suggested that length-weight relationships may vary according to factors such as food availability, feeding rate, gonad development and spawning period. The b values, calculated for the Italian seas, range from 2.86 to 3.14 (Tuscan coast and Sicilian Channel) (for both genders). In males the values of b range between 2.73 and 3.12 (Sicilian Channel and southern Tyrrhenian Sea), in females from 2.95 to 3.14 (Adriatic Sea and Sicilian Channel). A comparison between size-weight relationships, made in the Gulf of Gabès (Tunisia) through a covariance analysis, showed significant differences between males and females. This result differs from what was observed by other Authors in several areas. A morphometric and ultrastructural study of otoliths within the Triglidae family in centralnorthern Adriatic Sea, shows intra and interspecific changes in otolith shape linked to growth, species, sex and phylogenesis. A similarity can be found between species belonging to the same Genus, while differences between phylogenetically distinct species (e.g. L. cavillone and C. lucerna) and intraspecific differences between juveniles and adults were evidenced. Typically, males of the Triglidae family, C. lucerna included, mature earlier and at a smaller size than females. In the central-northern Adriatic Sea, sizes at 50% of sexual maturity, were estimated in 24.3 cm TL for females and 22.1 cm TL for males. Males mature at 19.2 cm TL (1.5 years old) whilst females mature at 21.6 cm TL (about 3 years old). It is observed that in Aegean Sea that maturity begins at the end of the third year for males and of the fourth year for females. Reproduction takes place along the Italian coasts between December and May, whilst along the French Mediterranean coast it occurs between January and April. It is proved the existence of a time-lag for reproductive processes of C. lucerna between the Mediterranean and North Atlantic waters. Breeding time of the Black Sea populations is reported to be from December to April and July. Spawning takes place in the Thermaikos Gulf and in the Iskenderun Bay from January to May and from December to May and in winter-spring with a peak in January-February in the Gulf of Gabès. Eggs are pelagic, spherical, smooth and not sticky. Important nursery areas were showed along the coastal strip in the vicinity of Arno, Magra and Serchio river mouths.This phenomenon was observed also in other Mediterranean and Atlantic areas. Along the Tuscany coast, juvenile (mode of about 4 cm TL), appear in December and a massive recruitment occurs in March-April. The same recruitment period is reported in Mediterranean. In the central-northern Adriatic Sea juveniles are found in spring-summer on sandy-muddy bottoms between 10 and 20 m depth, while adults prevail in autumn-winter, during the spawning period

The effects of exposure to severe hyperoxemia on neurological outcome and mortality after cardiac arrest

INTRODUCTION: Hyperoxemia during cardiac arrest (CA) may increase chances of successful resuscitation. However, episodes of severe hyperoxemia after intensive care unit admission occurs frequently (up to 60%), and these have been associated with higher mortality in CA patients. The impact of severe hyperoxemia on neurological outcome is more unclear. EVIDENCE ACQUISITION: We conducted a systematic review and meta-analysis on Pubmed and EMBASE to evaluate the effects of severe hyperoxemia according to arterial blood gas analysis on neurological outcome and mortality in patients resuscitated from CA and admitted to intensive care unit. EVIDENCE SYNTHESIS: Thirteen observational studies were included, eight of them reporting data on neurological outcome and ten on mortality. Most studies reported odds ratio adjusted for confounders. Severe hyperoxemia was associated with worse neurological outcome (OR 1.37 [95%CI 1.01,1.86], P=0.04) and higher mortality at longest follow-up (OR 1.32 [95%CI 1.11,1.57], P=0.002). Subgroup analyses according to timing of hyperoxemia showed that any hyperoxemia during the first 36 hours was associated with worse neurological outcome (OR 1.52 [95%CI 1.12,2.08], P=0.008) and higher mortality (OR 1.40 [95%CI 1.18,1.66], P=0.0001), whilst early hyperoxemia was not (neurological: P=0.29; mortality: P=0.19). Sensitivity analyses mostly confirmed the results of the primary analyses. CONCLUSIONS: Severe hyperoxemia is associated with worse neurological outcome and lower survival in CA survivors admitted to intensive care unit. Clinical efforts should be made to avoid severe hyperoxemia during at least the first 36 hours after cardiac arrest