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The westerly wind on the poleward side of the summer polar jet stream (PJS) over the Western Hemisphere has significantly weakened since the 1980s. A weak summer PJS causes warming surface temperatures and deficient precipitation over Alaska and western North America, favoring extreme wildfire events. This study investigates influences of Arctic sea ice loss on the summer PJS variability over the Western Hemisphere. Regression analysis first provides observational evidence that Arctic sea ice reduction is related to a weakening summer Western Hemisphere PJS at interannual time scales. Atmospheric model ensemble simulations are then used to demonstrate that Arctic sea ice loss significantly contributes to observed Western Hemisphere Arctic warming and reduced meridional temperature gradient between midlatitudes and the pole in the lower and middle troposphere, acting to weaken the troposphere zonal wind and vertical wind shear from 55° to 75°N, and about 20–30% of observed weakened summer PJS trend during 1979–2014. Observational analysis and the model-based results also indicate that a significant portion of the observed trends of the PJS and vertical wind shear during 1979–2014 might be attributed to the decadal variability of the summer North Atlantic Oscillation (NAO). In the future climate, as more and more ice melts in the summer, the weakening effect of sea ice on the PJS will continue and will be superimposed onto the natural decadal variability of the PJS. [ABSTRACT FROM AUTHOR]

Recent increases in turkey vulture (Cathartes aura) and black vulture (Coragyps atratus) populations in North America have been attributed in part to their success adapting to human-modified landscapes. However, the capacity for such landscapes to generate favorable roosting conditions for these species has not been thoroughly investigated. We assessed the role of anthropogenic and natural landscape elements on roosting habitat selection of 11 black and 7 turkey vultures in coastal South Carolina, USA using a GPS satellite transmitter dataset derived from previous research. Our dataset spanned 2006–2012 and contained data from 7916 nights of roosting. Landscape fragmentation, as measured by land cover richness, influenced roosting probability for both species in all seasons, showing either a positive relationship or peaking at intermediate values. Roosting probability of turkey vultures was maximized at intermediate road densities in three of four seasons, and black vultures showed a positive relationship with roads in fall, but no relationship throughout the rest of the year. Roosting probability of both species declined with increasing high density urban cover throughout most of the year. We suggest that landscape transformations lead to favorable roosting conditions for turkey vultures and black vultures, which has likely contributed to their recent proliferations across much of the Western Hemisphere. [ABSTRACT FROM AUTHOR]

This paper summarizes the current archaeological, physiographic, demographic, molecular, and bioarchaeological understanding of the initial peopling and subsequent population dynamics of South America. Well-dated sites point to a colonization by relatively few broad-spectrum foragers from northeastern Asia between ~13,000 and 12,000 cal BC via the Panamanian Peninsula. By ~11,500–11,000 cal BC, a number of regional, specialized bifacial technologies were developed, with evidence for the seasonal scheduling of resources and the colonization of extreme environments. Restricted mobility, landscape modification, and the cultivation of domesticates were underway by ~8000 cal BC. The early migration routes followed by colonists resulted in a broad east-west population structure among ancient South Americans. Genetic, demographic, and skeletal morphological data indicate that a subsequent demographically driven dispersal into South America largely replaced preexisting central Andeans ~5000 BC, due to increased fertility associated with the shift to agriculture. Beyond the Andes, however, there is little evidence of impact of these later expansions on foragers and horticulturists of the Amazon and Southern Cone who were largely descended from Paleoindians and early Holocene populations. [ABSTRACT FROM AUTHOR]

The Mascarene High (MH) is a semi-permanent subtropical high-pressure zone in the South Indian Ocean. Apart from its large influence on African and Australian weather patterns, it also helps in driving the inter-hemispheric circulation between the Indian Ocean in the south and subcontinental landmass in the north. Using observations and reanalysis products, this study for the first time investigates recent warming trend observed in the MH region during the Global Warming Hiatus (GWH) period (1998–2016). Significant positive trends are observed in sea surface temperature (SST), sea surface height (SSH) and oceanic heat content (OHC) during this period in the MH region. Mixed layer heat budget analysis reveals the dominant role of heat advection in the observed warming trend. During the GWH period, stronger zonal currents advect the warm waters from the Western Pacific (WP) towards the MH region via the Indonesian Throughflow (ITF). This warming in the MH reduces the sea level pressure therein and establishes a weak pressure gradient between the MH and the northern hemisphere landmass. This in-turn weakens the cross-equatorial winds in the western Indian Ocean. [ABSTRACT FROM AUTHOR]

Jellyfish (primarily scyphomedusae) fisheries have a long history in Asia, where jellyfish have been caught and processed as food for centuries. More recently, jellyfish fisheries have expanded to the Western Hemisphere, often driven by demand from Asian buyers and collapses of more traditional local fish stocks. Jellyfish fisheries have been attempted in numerous countries in North, Central, and South America, with varying degrees of success. Here, we chronicle the arrival of jellyfish fisheries in the Americas and summarize relevant information on jellyfish fishing, processing, and management. Processing technology for edible jellyfish has not advanced, and presents major concerns for environmental and human health. The development of alternative processing technologies would help to eliminate these concerns and may open up new opportunities for markets and species. We also examine the biodiversity of jellyfish species that are targeted for fisheries in the Americas. Establishment of new jellyfish fisheries appears possible, but requires a specific combination of factors including high abundances of particular species, processing knowledge dictated by the target market, and either inexpensive labor or industrialized processing facilities. More often than not, these factors are not altogether evaluated prior to attempting a new jellyfish fishery. As such, jellyfish fisheries are currently expanding much more rapidly than research on the subject, thereby putting ecosystems and stakeholders' livelihoods at risk. [ABSTRACT FROM AUTHOR]

Crucial aspects of a strong thermally-driven wind system in the Atacama Desert in northern Chile during the extended austral winter season (May-September) are studied using 2 years of measurement data from the Sierra Gorda 80-m meteorological mast (SGO, 22° 56′ 24″ S; 69° 7′ 58″ W, 2,069 m above sea level (a.s.l.)). Daily cycles of atmospheric variables reveal a diurnal (nocturnal) regime, with northwesterly (easterly) flow and maximum mean wind speed of 8 m/s (13 m/s) on average. These distinct regimes are caused by pronounced topographic conditions and the diurnal cycle of the local radiative balance. Wind speed extreme events of each regime are negatively correlated at the inter-daily time scale: High diurnal wind speed values are usually observed together with low nocturnal wind speed values and vice versa. The associated synoptic conditions indicate that upper-level troughs at the coastline of southwestern South America reinforce the diurnal northwesterly wind, whereas mean undisturbed upper-level conditions favor the development of the nocturnal easterly flow. We analyze the skill of the numerical weather model Global Forecast System (GFS) in predicting wind speed at SGO. Although forecasted wind speeds at 800 hPa do show the diurnal and nocturnal phases, observations at 80 m are strongly underestimated by the model. This causes a pronounced daily cycle of root-mean-squared error (RMSE) and bias in the forecasts. After applying a simple Model Output Statistics (MOS) post-processing, we achieve a good representation of the wind speed intra-daily and inter-daily variability, a first step toward reducing the uncertainties related to potential wind energy projects in the region. [ABSTRACT FROM AUTHOR]

Salvia subgenus Calosphace (Lamiaceae) is economically and ethnomedicinally significant and comprised of more than 500 species. Although strongly supported as monophyletic, it has received no comprehensive systematic research since the initial establishment of 91 taxonomic sections in 1939. Representative taxa of 73 sections of Calosphace were sampled to investigate the phylogenetic relationships and identify major lineages using chloroplast (intergenic spacer psbA- trnH) and nuclear ribosomal DNA (internal transcribed spacer). Phylogenetic analysis of the combined data sets established monophyly of seven sections ( Blakea, Corrugatae, Erythrostachys, Hastatae, Incarnatae, Microsphace, and Sigmoideae) and four major lineages ( S. axillaris, 'Hastatae clade', ' Uliginosae clade', and 'core Calosphace'). Sections spanning two or more centers of diversity are not supported by our results; rather, supported relationships exhibit significant geographic structure. Mexico is supported as the geographic origin of Calosphace, and no more than seven dispersal events to South America are required to account for current disjunct distributions. [ABSTRACT FROM AUTHOR]

Introduction: Over the past years, the incidence of thyroid cancer has surged not only in Germany but also in other countries of the Western hemisphere. This surge was first and foremost due to an increase of prognostically favorable ('low risk') papillary thyroid microcarcinomas, for which limited surgical procedures are often sufficient without loss of oncological benefit. These developments called for an update of the previous practice guideline to detail the surgical treatment options that are available for the various disease entities and tumor stages. Methods: The present German Association of Endocrine Surgeons practice guideline was developed on the basis of clinical evidence considering current national and international treatment recommendations through a formal expert consensus process in collaboration with the German Societies of General and Visceral Surgery, Endocrinology, Nuclear Medicine, Pathology, Radiooncology, Oncological Hematology, and a German thyroid cancer patient support organization. Results: The practice guideline for the surgical management of malignant thyroid tumors includes recommendations regarding preoperative workup; classification of locoregional nodes and terminology of surgical procedures; frequency, clinical, and histopathological features of occult and clinically apparent papillary, follicular, poorly differentiated, undifferentiated, and sporadic and hereditary medullary thyroid cancers, thyroid lymphoma and thyroid metastases from primaries outside the thyroid gland; extent of thyroidectomy; extent of lymph node dissection; aerodigestive tract resection; postoperative follow-up and surgery for recurrence and distant metastases. Conclusion: These evidence-based recommendations for surgical therapy reflect various 'treatment corridors' that are best discussed within multidisciplinary teams and the patient considering tumor type, stage, progression, and inherent surgical risk. [ABSTRACT FROM AUTHOR]

Raoiella indica Hirst (Acari: Tenuipalpidae) is a phytophagous mite that recently invaded the Western Hemisphere. This mite is a multivoltine and gregarious species that can reach very high population densities and cause significant damage to various palm species (Arecaceae). The predatory mite Amblyseius largoensis (Muma) (Acari: Phytoseiidae) has been found associated with R. indica in Florida. This study evaluated A. largoensis for potential to control R. indica by (1) determining predator preferences among developmental stages of R. indica, and (2) estimating predator functional and numerical responses to varying densities of its most preferred prey-stage. Under no-choice conditions A. largoensis consumed significantly more eggs than other stages of R. indica. In choice tests A. largoensis showed a significant preference for R. indica eggs over all other prey stages. Amblyseius largoensis displayed a type II functional response showing an increase in number of prey killed with an increase in prey population density. Consumption of prey stabilized at approximately 45 eggs/day, the level at which oviposition by the predator was maximized (2.36 ± 0.11 eggs/day; mean ± SEM). Results of this study suggest that A. largoensis can play a role in controlling R. indica populations, particularly when prey densities are low. [ABSTRACT FROM AUTHOR]

The Monroe Doctrine had been a pillar of US foreign policy in the nineteenth century, but its importance in the twentieth century is disputed. On the one hand, it laid the grounds for American expansion in the Western Hemisphere and, on the other, it provided a framework of reciprocal non-interference in transatlantic relations. Therefore, a reconsideration of its impact is relevant to the discussion of the tension between internationalism and isolationism. An assessment of the relevance of the Monroe Doctrine in twentieth-century US diplomacy must take into account that (i) it outlined a space-based, regionalist view of world affairs and (ii) it expressed widespread notions of American culture, history, and national identity. [ABSTRACT FROM AUTHOR]

In addition to its global North–South anisotropy, there are two other enigmatic seismological observations related to the Earth’s inner core: asymmetry between its eastern and western hemispheres and the presence of a layer of reduced seismic velocity at the base of the outer core. This 250-km-thick layer has been interpreted as a stably stratified region of reduced composition in light elements. Here we show that this layer can be generated by simultaneous crystallization and melting at the surface of the inner core, and that a translational mode of thermal convection in the inner core can produce enough melting and crystallization on each hemisphere respectively for the dense layer to develop. The dynamical model we propose introduces a clear asymmetry between a melting and a crystallizing hemisphere which forms a basis for also explaining the East–West asymmetry. The present translation rate is found to be typically 100 million years for the inner core to be entirely renewed, which is one to two orders of magnitude faster than the growth rate of the inner core’s radius. The resulting strong asymmetry of buoyancy flux caused by light elements is anticipated to have an impact on the dynamics of the outer core and on the geodynamo. [ABSTRACT FROM AUTHOR]

Using monthly data from the European Center for Medium-Range Weather Forecast 40-year reanalysis (ERA-40), we have revealed a teleconnection pattern over the extratropical Northern Hemisphere through the empirical orthogonal function analysis of summer upper-tropospheric eddy temperature. When temperature is higher (lower) over the Eastern Hemisphere (EH), it is lower (higher) over the Western Hemisphere (WH). The teleconnection manifested by this out-of-phase relationship is referred to as the Asian–Pacific oscillation (APO). The values of an index measuring the teleconnection are high before 1976 and low afterwards, showing a downward trend of the stationary wave at a rate of 4% per year during 1958–2001. The index also exhibits apparent interannual variations. When the APO index is high, anomalous upper-tropospheric highs (lows) appear over EH (WH). The formation of APO is likely associated with a zonal vertical circulation in the troposphere. Unforced control runs of both the NCAR Community Atmospheric Model version 3 and the Community Climate System Model version 3 capture the major characteristics of the teleconnection pattern and its associated vertical structure. The APO variability is closely associated with sea surface temperature (SST) in the Pacific, with a significantly positive correlation between APO and SST in the extratropical North Pacific and a significantly negative correlation in the tropical eastern Pacific. Sensitivity experiments show that the anomalies of SST over these two regions influence the APO intensity, but their effects are opposite to each other. Compared to the observation, the positive and negative anomalous centers of the extratropical tropospheric temperature triggered by the SST anomalies have a smaller spatial scale. [ABSTRACT FROM AUTHOR]

Seismic waves sampling the top 100 km of the Earth's inner core reveal that the eastern hemisphere (40° E–180° E) is seismically faster, more isotropic and more attenuating than the western hemisphere. The origin of this hemispherical dichotomy is a challenging problem for our understanding of the Earth as a system of dynamically coupled layers. Previously, laboratory experiments have established that thermal control from the lower mantle can drastically affect fluid flow in the outer core, which in turn can induce textural heterogeneity on the inner core solidification front. The resulting texture should be consistent with other expected manifestations of thermal mantle control on the geodynamo, specifically magnetic flux concentrations in the time-average palaeomagnetic field over the past 5 Myr, and preferred eddy locations in flows imaged below the core–mantle boundary by the analysis of historical geomagnetic secular variation. Here we show that a single model of thermochemical convection and dynamo action can account for all these effects by producing a large-scale, long-term outer core flow that couples the heterogeneity of the inner core with that of the lower mantle. The main feature of this thermochemical ‘wind’ is a cyclonic circulation below Asia, which concentrates magnetic field on the core–mantle boundary at the observed location and locally agrees with core flow images. This wind also causes anomalously high rates of light element release in the eastern hemisphere of the inner core boundary, suggesting that lateral seismic anomalies at the top of the inner core result from mantle-induced variations in its freezing rate. [ABSTRACT FROM AUTHOR]

Using a comparative-static general equilibrium model in the context of the Western Hemisphere, this paper compares the economic effects of a "hub-and spokes" type of bilateral trade configuration (with Chile being the hub) with those of a more comprehensive regional FTA (namely, the FTAA). The model is augmented to account for the possibility of technology spillovers and its effective assimilation among participating economies. In particular, absorptive capacity, governance factor, proximity and socio-institutional congruence conjointly determine an economy's capacity to capture the technology that is transmitted from the developed spoke United States to other regions. [ABSTRACT FROM AUTHOR]

The first part of my presentation is a short outline of how a feminist, process-oriented, i.e. in a Whiteheadian tradition, business ethics may look like. In the second part, I want to apply this approach in the field of American foreign trade policy concerning the extension of the North American Free Trade Area (NAFTA) to a free trade zone of the Western Hemisphere. I want to focus on ethical problems for the business of the Free Trade Area of the Americas. By taking my business ethics approach into consideration, I want to open up perspectives for a Whiteheadian view of the problem of the Free Trade Area. [ABSTRACT FROM AUTHOR]

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The article focuses on the difference in the views and treatment on surgical gastric cancer epidemiology between the Western and Eastern hemispheres. In the West, the frequency of carcinomas in the proximal third of the stomach is increasing alarmingly, whereas in the East, cancers of the middle and distal third are still prevailing. cancers. In the Eastern hemisphere, up to 70% of all gastric cancers are diagnosed as early cancers. In the Western hemisphere, the rate of gastric cancers identified as early cancers accounts for only about 15%. Almost 50% of all patients are admitted for treatment when they are already harboring stage III or IV disease.

Offers a look at scientists from the Western hemisphere who have decided to move East in their course of studies. Why Asian universities and institutes are beginning to welcome the immigration of Western scientists; What such institutes are doing in an attempt to attract new faculty; Accounts from scientists from the United States and Great Britain who have moved to Japan and China in order to pursue their work.

Asajirella gelatinosa, a freshwater bryozoan known previously only from eastern Asia is now reported in the Republic of Panama. Colonies were collected during April 1992 in the broad reaches of the lower Rio Chagres as it enters Gatun Lake, part of the Panama Canal system. Asubsequent collection in 1998 included large colonies and numerous statoblasts from a region upstream of this site in the impounded Lago Alajuela (Madden Lake). Colonies and statoblasts resemble those from Japan in almost every detail. Human transport of statoblasts is a likely cause of this disjunct distribution. [ABSTRACT FROM AUTHOR]

This article focuses on a study conducted by Johanna Nichols, a researcher at the University of California at Berkeley, on the origin of languages. The results suggest that languages arose long before modern humans spread out around the globe, while they were still inhabiting the tropical regions of Asia, Africa and the Near East. Nichols, who reported her findings in a press conference at the annual meeting of the American Association for the Advancement of Science in San Francisco, estimated the ages of modern languages on the basis of grammatical comparisons of certain features in language that change little over time. Her conclusions concerning the age of New World languages support recent genetic evidence that native populations in the Westem Hemisphere are much older than generally assumed.