957 resultados para Emergence Time Period
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Context: Information currently available on the trafficking of minors in the U.S. for commercial sexual exploitation includes approximations of the numbers involved, risk factors that increase the likelihood of victimization and methods of recruitment and control. However, specific characteristics about this vulnerable population remain largely unknown. Objective: This article has two distinct purposes. The first is to provide the reader with an overview of available information on minor sex trafficking in the U.S. The second is to present findings and discuss policy, research, and educational implications from secondary data analysis of 115 cases of minor sex trafficking in the U.S. Design: Minor sex trafficking cases were identified through two main venues - a review of U.S. Department of Justice press releases of human trafficking cases and an online search of media reports. Searches covered the time period from October 28, 2000, which coincided with the passage of the VTVPA through October 31, 2009. Cases were included in analysis if the incident involved at least one victim under the age of 18, occurred in the U.S., and at least one perpetrator had been arrested, indicted, or convicted. Results: A total of 115 separate incidents involving at least 153 victims were located. These occurrences involved 215 perpetrators, with the majority of them having been convicted (n = 117, 53.4%), The number of victims involved in a single incident ranged from 1 to 9. Over 90% of victims were female who ranged in age from 5 to 17 years. There were more U.S. minor victims than those from other countries. Victims had been in captivity from less than 6 months to 5 years. Minors most commonly fell into exploitation through some type of false promise indicated (16.3%, n = 25), followed by kidnapping (9.8%, n = 15). Over a fifth of the sample (22.2%, n = 34) were abused through two commercial sex practices, with almost all (94.1%, n = 144) used in prostitution. One of every five victims (24.8%, n = 38) had been advertised on an Internet website. Conclusions: Results of a review of known information about minor sex trafficking and findings from analysis of 115 incidents of the sex trafficking of youth in the U.S. indicate a need for stronger legislation to educate various professional groups, more comprehensive services for victims, stricter laws for pimps and traffickers, and preventive educational interventions beginning at a young age.
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Visual short-term memory (VSTM) is the storage of visual information over a brief time period (usually a few seconds or less). Over the past decade, the most popular task for studying VSTM in humans has been the change detection task. In this task, subjects must remember several visual items per trial in order to identify a change following a brief delay interval. Results from change detection tasks have shown that VSTM is limited; humans are only able to accurately hold a few visual items in mind over a brief delay. However, there has been much debate in regard to the structure or cause of these limitations. The two most popular conceptualizations of VSTM limitations in recent years have been the fixed-capacity model and the continuous-resource model. The fixed-capacity model proposes a discrete limit on the total number of visual items that can be stored in VSTM. The continuous-resource model proposes a continuous-resource that can be allocated among many visual items in VSTM, with noise in item memory increasing as the number of items to be remembered increases. While VSTM is far from being completely understood in humans, even less is known about VSTM in non-human animals, including the rhesus monkey (Macaca mulatta). Given that rhesus monkeys are the premier medical model for humans, it is important to understand their VSTM if they are to contribute to understanding human memory. The primary goals of this study were to train and test rhesus monkeys and humans in change detection in order to directly compare VSTM between the two species and explore the possibility that direct species comparison might shed light on the fixed-capacity vs. continuous-resource models of VSTM. The comparative results suggest qualitatively similar VSTM for the two species through converging evidence supporting the continuous-resource model and thereby establish rhesus monkeys as a good system for exploring neurophysiological correlates of VSTM.
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The purpose of the study was to evaluate in vitro calcification potential among liposomes composed of phospholipids with variations in fatty acid chains and polar head groups. The liposome was also modified by utilizing mixed phospholipids, incorporation of different types of protein to the liposome, or complexing with various collagen preparations. The samples were then incubated in a metastable calcium phosphate solution for the proposed time period. Calcium and phosphate uptake were measured. Resulting precipitates were processed for x-ray diffraction and electron microscopy. Acidic phospholipid, Dioleoylphosphatidic acid and mixed phospholipids, Dioleoylphosphatidic acid/Dipalmitoylphosphatidylethanolamine liposomes calcified at a faster rate and to a greater degree than other phospholipids tested. The incorporation of polylysine, fibronectin, bone protein, or the complexing with collagen decreased the rate and amount of calcification. Electron microscopy demonstrated the similarity of the calcified collagen-liposome complex to the natural calcification matrix. These preparations may be used as a model to study the role of membrane lipids and collagen-phospholipid during the process of calcification.^ The in vivo study was designed to determine whether the potential existed for the promotion of bone healing by the synthetic liposome-collagen complex. The implant materials were modified to provide decreased antigenicity, biocompatability while maintaining their bone conduction properties. The samples were placed subcutaneously and/or subperiosteally and/or in 8 mm calvarium defects of adult rats. Histological and immunological studies demonstrated that the implant itself retained minimal antigenicity and did not inhibit bone formation. However, modification of the implant may contain the bone induction property and be utilized to stimulate bony healing. ^
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Gastrin-releasing peptide (GRP) and other bombesin-like peptides stimulate hormone secretion and cell proliferation by binding to specific G-protein-coupled receptors. Three studies were performed to identify potential mechanisms involved in GRP/bombesin receptor regulation.^ Although bombesin receptors are localized throughout the gastrointestinal tract, few gastrointestinal cell lines are available to study bombesin action. In the first study, the binding and function of bombesin receptors in the human HuTu-80 duodenal cancer cell line were characterized. ($\sp{125}$I-Tyr$\sp4$) bombesin bound with high affinity to a GRP-preferring receptor. Bombesin treatment increased IP$\sb3$ production, but had no effect on cell proliferation. Similar processing of ($\sp{125}$I-Tyr$\sp4$) bombesin and of GRP-receptors was observed in HuTu-80 cells and Swiss 3T3 fibroblasts, a cell line which mitogenically responds to bombesin. Therefore, the lack of a bombesin mitogenic effect in HuTu-80 cells is not due to unusual processing of ($\sp{125}$I-Tyr$\sp4$) bombesin or rapid GRP-receptor down-regulation.^ In the second study, a bombesin antagonist was developed to study the processing and regulatory events after antagonist binding. As previously shown, receptor bound agonist, ($\sp{125}$I-Tyr$\sp4$) bombesin, was rapidly internalized and degraded in chloroquine-sensitive compartments. Interestingly, receptor-bound antagonist, ($\sp{125}$I-D-Tyr$\sp6$) bombesin(6-13)PA was not internalized, but degraded at the cell-surface. In contrast to bombesin, (D-Tyr$\sp6$) bombesin(6-13)PA treatment did not cause receptor internalization. Together these results demonstrate that receptor regulation and receptor-mediated processing of antagonist is different from that of agonist.^ Bombesin receptors undergo acute desensitization. By analogy to other G-protein-coupled receptors, a potential desensitization mechanism may involve receptor phosphorylation. In the final study, $\sp{32}$P-labelled Swiss 3T3 fibroblasts and CHO-mBR1 cells were treated with bombesin and the GRP-receptor was immunoprecipitated. In both cell lines, bombesin treatment markedly stimulated GRP-receptor phosphorylation. Furthermore, bombesin-stimulated GRP-receptor phosphorylation occurred within the same time period as bombesin-stimulated desensitization, demonstrating that these two processes are correlated.^ In conclusion, these studies of GRP-receptor regulation further our understanding of bombesin action and provide insight into G-protein-coupled receptor regulation in general. ^
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The objective of this study is to identify the relationship between population density and the initial stages of the spread of disease in a local population. This study proposes to concentrate on the question of how population density affects the distribution of the susceptible individuals in a local population and thus affects the spread of the disease, measles. Population density is measured by the average of the number of contacts with susceptible individuals by each individual in the population during a fixed-length time period. The term “contact with susceptible individuals” means sufficient contact between two people for the disease to pass from an infectious person to a susceptible person. The fixed-length time period is taken to be the average length of time an infected person is infectious without symptoms of the disease. For this study of measles, the time period will be seven days. ^ While much attention has been given to modeling the entire epidemic process of measles, attempts have not been made to study the characteristics of contact rates required to initiate an epidemic. This study explores the relationship between population density, given a specific herd immunity rate in the population, and initial rate of the spread of the disease by considering the underlying distribution of contacts with susceptibles by the individuals in the population. ^ This study does not seek to model an entire measles epidemic, but to model the above stated relationship for the local population within which the first infective person is introduced. This study describes the mathematical relationship between population density parameters and contact distribution parameters. ^ The results are displayed in graphs that show the effects of different population densities on the spread of disease. The results support the idea that the number of new infectives is strongly related to the distribution of susceptible contacts. The results also show large differences in the epidemic measures between populations with densities equal to four versus three. ^
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Beginning in the early 1980s, the health care system experienced momentous realignments. Fundamental changes in structures of traditional health care organizations, shifts in authority and relationships of professionals and institutions, and the increasing influence of managed care contributed to a relatively stable industry entering into a state of turbulence. The dynamics of these changes are recurring themes in the health services literature. The purpose of this dissertation was to examine the content of this literature over a defined time period and within the perspective of a theory of organizational change. ^ Using a theoretical framework based upon the organizational theory known as Organizational Ecology, secondary data from the period between 1983 and 1994 was reviewed. Analysis of the literature identified through a defined search methodology was focused upon determining the manner in which the literature characterized changes that were described. Using a model constructed from fundamentals of Organizational Ecology with which to structure an assessment of content, literature was summarized for the manner and extent of change in specific organizational forms and for the changes in emphasis by the environmental dynamics directing changes in the population of organizations. Although it was not the intent of the analysis to substantiate causal relationships between environmental resources selected as the determinants of organizational change and the observed changes in organizational forms, the structured review of content of the literature established a strong basis for inferring such a relationship. ^ The results of the integrative review of the literature and the power of the appraisal achieved through the theoretical framework constructed for the analysis indicate that there is considerable value in such an approach. An historical perspective on changes which have transformed the health care system developed within a defined organizational theory provide a unique insight into these changes and indicate the need for further development of such an analytical model. ^
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The abundance of many invertebrates with planktonic larval stages can be determined shortly after they reach the benthos. In this study, we quantified patterns of abundance and habitat utilization of early benthic phases of the American lobster Homarus americanus and the rock crab Cancer irroratus. These 2 decapods are among the most common and abundant macroinvertebrates in coastal zones of the Gulf of Maine, with similar densities of larger individuals. Settlement and early postsettlement survival indicate that lobsters are highly substrate-specific early in life, settling predominantly in cobble beds. Crabs appear to be less selective, setting both in cobble and sand. Cumulative settlement of crabs, inferred from weekly censuses over the summer, was an order of magnitude greater than that of lobsters over the same time period. However, only crabs showed significant postsettlement losses. Although the identity of specific predators is unknown, predator exclusion experiments and placement of vacant uninhabited nursery habitat suggested that post-settlement mortality rather than emigration was responsible for these losses. The selective habitat-seeking behavior and lower post-settlement mortality of lobsters is consistent with their lower fecundity and later onset of reproductive maturity. The patterns observed for crabs, however, suggest a different strategy which is more in accordance with their higher fecundity and earlier onset of maturity. It is possible that lower fecundity but greater per-egg investment, along with strict habitat selection at settlement and lower post-settlement mortality, allows adult lobster populations to equal adult populations of crabs. This occurs despite crabs being more fecund and less habitat-selective settlers but sustaining higher postsettlement mortality.
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This study investigates the characteristics of the quasi 16-day wave in the mesosphere during boreal winter 2011/2012 using observations of water vapor from ground-based microwave radiometers and satellite data. The ground-based microwave radiometers are located in Seoul (South Korea, 37° N), Bern (Switzerland, 47° N) and Sodankylä (Finland, 67° N). The quasi 16-day wave is observed in the mesosphere at all three locations, while the dominant period increases with latitude from 15 days at Seoul to 20 days at Sodankylä. The observed evolution of the quasi 16-day wave confirms that the wave activity is strongly decreased during a sudden stratospheric warming that occurred in mid-January 2012. Using satellite data from the Microwave Limb Sounder on the Aura satellite, we examine the zonal characteristics of the quasi 16-day wave and conclude that the observed waves above the mid-latitudinal stations Seoul and Bern are eastward-propagating s=−1 planetary waves with periods of 15 to 16 days, while the observed oscillation above the polar station Sodankylä is a standing oscillation with a period of approximately 20 days. The strongest relative wave amplitudes in water vapor during the investigated time period are approximately 15%. The wave activity varies strongly along a latitude circle. The activity of the quasi 16-day wave in mesospheric water vapor during boreal winter 2011/2012 is strongest over Northern Europe, the North Atlantic ocean and North-West Canada. The region of highest wave activity seems to be related to the position of the polar vortex. We conclude that the classic approach to characterize planetary waves zonally averaged along a latitude circle is not sufficient to explain the local observations because of the strong longitudinal dependence of the wave activity.
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Since November 1994, the GROund-based Millimeter-wave Ozone Spectrometer (GROMOS) measures stratospheric and lower mesospheric ozone in Bern, Switzerland (47.95° N, 7.44° E). GROMOS is part of the Network for the Detection of Atmospheric Composition Change (NDACC). In July 2009, a Fast-Fourier-Transform spectrometer (FFTS) has been added as backend to GROMOS. The new FFTS and the original filter bench (FB) measured parallel for over two years. In October 2011, the FB has been turned off and the FFTS is now used to continue the ozone time series. For a consolidated ozone time series in the frame of NDACC, the quality of the stratospheric ozone profiles obtained with the FFTS has to be assessed. The FFTS results from July 2009 to December 2011 are compared to ozone profiles retrieved by the FB. FFTS and FB of the GROMOS microwave radiometer agree within 5% above 20 hPa. A later harmonization of both time series will be realized by taking the FFTS as benchmark for the FB. Ozone profiles from the FFTS are also compared to coinciding lidar measurements from the Observatoire Haute Provence (OHP), France. For the time period studied a maximum mean difference (lidar – GROMOS FFTS) of +3.8% at 3.1 hPa and a minimum mean difference of +1.4% at 8 hPa is found. Further, intercomparisons with ozone profiles from other independent instruments are performed: satellite measurements include MIPAS onboard ENVISAT, SABER onboard TIMED, MLS onboard EOS Aura and ACE-FTS onboard SCISAT-1. Additionally, ozonesondes launched from Payerne, Switzerland, are used in the lower stratosphere. Mean relative differences of GROMOS FFTS and these independent instruments are less than 10% between 50 and 0.1 hPa.
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Abstract. In this paper, we compare the diurnal variations in middle-atmospheric water vapor as measured by two ground-based microwave radiometers in the Alpine region near Bern, Switzerland. The observational data set is also compared to data from the chemistry–climate model WACCM. Due to the small diurnal variations of usually less than 1%, averages over extended time periods are required. Therefore, two time periods of five months each, December to April and June to October, were taken for the comparison. The diurnal variations from the observational data agree well with each other in amplitude and phase. The linear correlation coefficients range from 0.8 in the upper stratosphere to 0.5 in the upper mesosphere. The observed diurnal variability is significant at all pressure levels within the sensitivity of the instruments. Comparing our observations with WACCM, we find that the agreement of the phase of the diurnal cycle between observations and model is better from December to April than from June to October. The amplitudes of the diurnal variations for both time periods increase with altitude in WACCM, but remain approximately constant at 0.05 ppm in the observations. The WACCM data are used to separate the processes that lead to diurnal variations in middle-atmospheric water vapor above Bern. The dominating processes were found to be meridional advection below 0.1 hPa, vertical advection between 0.1 and 0.02 hPa and (photo-)chemistry above 0.02 hPa. The contribution of zonal advection is small. The highest diurnal variations in water vapor as seen in the WACCM data are found in the mesopause region during the time period from June to October with diurnal amplitudes of 0.2 ppm (approximately 5% in relative units).
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In order to reconstruct the temperature of the North Greenland Ice Core Project (NGRIP) site, new measurements of δ15N have been performed covering the time period from the beginning of the Holocene to Dansgaard–Oeschger (DO) event 8. Together with previously measured and mostly published δ15N data, we present for the first time a NGRIP temperature reconstruction for the whole last glacial period from 10 to 120 kyr b2k (thousand years before 2000 AD) including every DO event based on δ15N isotope measurements combined with a firn densification and heat diffusion model. The detected temperature rises at the onset of DO events range from 5 °C (DO 25) up to 16.5 °C (DO 11) with an uncertainty of ±3 °C. To bring measured and modelled data into agreement, we had to reduce the accumulation rate given by the NGRIP ss09sea06bm timescale in some periods by 30 to 35%, especially during the last glacial maximum. A comparison between reconstructed temperature and δ18Oice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We evidence an anticorrelation between the variations of the δ18Oice sensitivity to temperature (referred to as α) and obliquity in agreement with a simple Rayleigh distillation model. Finally, we suggest that α might be influenced by the Northern Hemisphere ice sheet volume.
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This study investigates the characteristics of the quasi 16-day wave in the mesosphere during boreal winter 2011/2012 using observations of water vapor from ground-based microwave radiometers and satellite data. The ground-based microwave radiometers are located in Seoul (South Korea, 37° N), Bern (Switzerland, 47° N) and Sodankylä (Finland, 67° N). The quasi 16-day wave is observed in the mesosphere at all three locations, while the dominant period increases with latitude from 15 days at Seoul to 20 days at Sodankylä. The observed evolution of the quasi 16-day wave confirms that the wave activity is strongly decreased during a sudden stratospheric warming that occurred in mid-January 2012. Using satellite data from the Microwave Limb Sounder on the Aura satellite, we examine the zonal characteristics of the quasi 16-day wave and conclude that the observed waves above the midlatitudinal stations Seoul and Bern are eastward-propagating s = −1 planetary waves with periods of 15 to 16 days, while the observed oscillation above the polar station Sodankylä is a standing wave with a period of approximately 20 days. The strongest relative wave amplitudes in water vapor during the investigated time period are approximately 15%. The wave activity varies strongly along a latitude circle. The activity of the quasi 16-day wave in mesospheric water vapor during boreal winter 2011/2012 is strongest over northern Europe, the North Atlantic Ocean and northwestern Canada. The region of highest wave activity seems to be related to the position of the polar vortex. We conclude that the classic approach to characterize planetary waves zonally averaged along a latitude circle is not sufficient to explain the local observations because of the strong longitudinal dependence of the wave activity.
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Terrestrial records of past climatic conditions, such as lake sediments and speleothems, provide data of great importance for understanding environmental changes. However, unlike marine and ice core records, terrestrial palaeodata are often not available in databases or in a format that is easily accessible to the non-specialist. As a consequence, many excellent terrestrial records are unknown to the broader palaeoclimate community and are not included in compilations, comparisons, or modelling exercises. Here we present a compilation of Western European terrestrial palaeo-records covering, entirely or partially, the 60–8-ka INTIMATE time period. The compilation contains 56 natural archives, including lake records, speleothems, ice cores, and terrestrial proxies in marine records. The compilation is limited to include records of high temporal resolution and/or records that provide climate proxies or quantitative reconstructions of environmental parameters, such as temperature or precipitation, and that are of relevance and interest to a broader community. We briefly review the different types of terrestrial archives, their respective proxies, their interpretation and their application for palaeoclimatic reconstructions. We also discuss the importance of independent chronologies and the issue of record synchronization. The aim of this exercise is to provide the wider palaeo-community with a consistent compilation of high-quality terrestrial records, to facilitate model-data comparisons, and to identify key areas of interest for future investigations. We use the compilation to investigate Western European latitudinal climate gradients during the deglacial period and, despite of poorly constrained chronologies for the older records, we summarize the main results obtained from NW and SW European terrestrial records before the LGM.
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Background Concurrent cardiac diseases are frequent among elderly patients and invite simultaneous treatment to ensure an overall favourable patient outcome. Aim To investigate the feasibility of combined single-session percutaneous cardiac interventions in the era of transcatheter aortic valve implantation (TAVI). Methods This prospective, case–control study included 10 consecutive patients treated with TAVI, left atrial appendage occlusion and percutaneous coronary interventions. Some in addition had patent foramen ovale or atrial septal defect closure in the same session. The patients were matched in a 1:10 manner with TAVI-only cases treated within the same time period at the same institution regarding their baseline factors. The outcome was validated according to the Valve Academic Research Consortium (VARC) criteria. Results Procedural time (126±42 vs 83±40 min, p=0.0016), radiation time (34±8 vs 22±12 min, p=0.0001) and contrast dye (397±89 vs 250±105 mL, p<0.0001) were higher in the combined intervention group than in the TAVI-only group. Despite these drawbacks, no difference in the VARC endpoints was evident during the in-hospital period and after 30 days (VARC combined safety endpoint 32% for TAVI only and 20% for combined intervention, p=1.0). Conclusions Transcatheter treatment of combined cardiac diseases is feasible even in a single session in a high-volume centre with experienced operators.
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Objectives. Despite the large body of literature on bereavement, little is known about the impact of sociohistorical context on individual reactions to spousal loss. This study examines the effect of marital status, time period and gender on physical and mental health, and whether reported difficulties following spousal loss differ at 2 distinctive time periods. Method. Two cohorts of older bereaved persons (n = 753) in Switzerland, surveyed in 1979 and 2011, were compared regarding their reports of difficulties related to marital loss. The bereaved spouses were also compared with a group of married contemporaries (n = 1,517) regarding subjective health and depressive symptoms. Results. Marital status and gender each have independent effects on subjective health and depressive symptoms. The effects of widowhood on subjective health differed significantly at both time points. Widowed individuals in 2011, especially women, reported fewer social and financial difficulties than their counterparts in 1979. However, the effect of widowhood on depressive symptoms and psychological difficulties did not differ significantly across time points. Discussion. Social changes in the late 20th century may be protective for older adults’ physical, social, and financial well-being in the face of spousal loss, yet these changes do not alleviate widow(er)s’ psychological distress.