bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computation of the Standardized Precipitation Index (SPI) and Its Use to Assess Drought Occurrences in Cameroon over Recent Decades
Authors: Guenang Guy Merlin , Kamga F. Mkankam 
Published: August 2014

AbstractThe standardized precipitation index (SPI) is computed and analyzed using 55 years of precipitation data recorded in 24 observation stations in Cameroon along with University of East Anglia Climate Research Unit (CRU) spatialized data. Four statistical distribution functions (gamma, exponential, Weibull, and lognormal) are first fitted to data accumulated for various time scales, and the appropriate functions are selected on the basis of the Anderson–Darling goodness-of-fit statistic. For short time scales (up to 6 months) and for stations above 10°N, the gamma distribution is the most frequent choice; below this belt, the Weibull distribution predominates. For longer than 6-month time scales, there are no consistent patterns of fitted distributions. After calculating the SPI in the usual way, operational drought thresholds that are based on an objective method are determined at each station. These thresholds are useful in drought-response decision making. From SPI time series, episodes of severe and extreme droughts are identified at many stations during the study period. Moderate/severe drought occurrences are intra-annual in short time scales and interannual for long time scales (greater than 9 months), usually spanning many years. The SPI calculated from CRU gridded precipitation shows similar results, with some discrepancies at longer scales. Thus, the spatialized dataset can be used to extend such studies to a larger region—especially data-scarce areas.
The Turbulent Structure and Diurnal Growth of the Saharan Atmospheric Boundary Layer
Authors: Garcia-Carreras L. , Parker D. J. , Marsham J. H. , Rosenberg P. D. , Brooks I. M. , Lock A. P. , Marenco F. , McQuaid J. B. , Hobby M. 
Published: August 2014

Abstract
The turbulent structure and growth of the remote Saharan atmospheric boundary layer (ABL) is described with in situ radiosonde and aircraft measurements and a large-eddy simulation model. A month of radiosonde data from June 2011 provides a mean profile of the midday Saharan ABL, which is characterized by a well-mixed convective boundary layer, capped by a small temperature inversion (&lt;1 K) and a deep, near-neutral residual layer. The boundary layer depth varies by up to 100% over horizontal distances of a few kilometers due to turbulent processes alone. The distinctive vertical structure also leads to unique boundary layer processes, such as detrainment of the warmest plumes across the weak temperature inversion, which slows down the warming and growth of the convective boundary layer. As the boundary layer grows, overshooting plumes can also entrain free-tropospheric air into the residual layer, forming a second entrainment zone that acts to maintain the inversion above the convective boundary layer, thus slowing down boundary layer growth further. A single-column model is unable to accurately reproduce the evolution of the Saharan boundary layer, highlighting the difficulty of representing such processes in large-scale models. These boundary layer processes are special to the Sahara, and possibly hot, dry, desert environments in general, and have implications for the large-scale structure of the Saharan heat low. The growth of the boundary layer influences the vertical redistribution of moisture and dust, and the spatial coverage and duration of clouds, with large-scale dynamical and radiative implications.
Stratospheric Wave–Mean Flow Feedbacks and Sudden Stratospheric Warmings in a Simple Model Forced by Upward Wave Activity Flux
Authors: Sjoberg Jeremiah P. , Birner Thomas 
Published: August 2014

Abstract
A classic result of studying stratospheric wave–mean flow interactions presented by Holton and Mass is that, for constant incoming wave forcing (at a notional tropopause), a vacillating stratospheric response may ensue. Simple models, such as the Holton–Mass model, typically prescribe the incoming wave forcing in terms of geopotential perturbation, which is not a proxy for upward wave activity flux. Here, the authors reformulate the Holton–Mass model such that incoming upward wave activity flux is prescribed. The Holton–Mass model contains a positive wave–mean flow feedback whereby wave forcing decelerates the mean flow, allowing enhanced wave propagation, which then further decelerates the mean flow, etc., until the mean flow no longer supports wave propagation. By specifying incoming wave activity flux, this feedback is constrained to the model interior. Bistability—where the zonal wind may exist at one of two distinct steady states for a given incoming wave forcing—is maintained in this reformulated model. The model is perturbed with transient pulses of upward wave activity flux to produce transitions between the two stable states. A minimum of integrated incoming wave activity flux necessary to force these sudden stratospheric warming–like transitions exists for pulses with time scales on the order of 10 days, arising from a wave time scale internal to the model at which forcing produces the strongest mean-flow response. The authors examine how the tropopause affects the internal feedback for this model setup and find that the tropopause inversion layer may potentially provide an important source of wave activity in the lower stratosphere.
Variability in the South Atlantic Anticyclone and the Atlantic Niño Mode*
Authors: Lübbecke Joke F. , Burls Natalie J. , Reason Chris J. C. , McPhaden Michael J. 
Published: August 2014

Abstract
Previous studies have argued that the strength of the South Atlantic subtropical high pressure system, referred to as the South Atlantic anticyclone (SAA), modulates sea surface temperature (SST) anomalies in the eastern equatorial Atlantic. Using ocean and atmosphere reanalysis products, it is shown here that the strength of the SAA from February to May impacts the timing of the cold tongue onset and the intensity of its development in the eastern equatorial Atlantic via anomalous tropical wind power. This modulation in the timing and amplitude of seasonal cold tongue development manifests itself via SST anomalies peaking between June and August. The timing and impact of this connection is not completely symmetric for warm and cold events. For cold events, an anomalously strong SAA in February and March leads to positive wind power anomalies from February to June resulting in an early cold tongue onset and subsequent cold SST anomalies in June and July. For warm events, the anomalously weak SAA persists until May, generating negative wind power anomalies that lead to a late cold tongue onset as well as a suppression of the cold tongue development and associated warm SST anomalies. Mechanisms by which SAA-induced wind power variations south of the equator influence eastern equatorial Atlantic SST are discussed, including ocean adjustment via Rossby and Kelvin wave propagation, meridional advection, and local intraseasonal wind variations.
An Isentropic Analysis of the Temporal Evolution of East Asian Cold Air Outbreaks
Authors: Shoji Takamichi , Kanno Yuki , Iwasaki Toshiki , Takaya Koutarou 
Published: August 2014

Abstract
The equatorward cold airmass flux below potential temperature θT = 280 K across 45°N integrated from 90°E to 180° is used as an index to quantitatively measure cold air outbreaks (CAOs) in the East Asian winter monsoon. Intermittent CAOs over East Asia significantly contribute to the global equatorward cold airmass flux. An autocorrelation analysis indicates that CAO events persist for approximately 5 days. The geographical distributions of lagged correlations/regressions with the CAO index (CAOI) clarify the temporal evolution of synoptic conditions associated with CAOs. The developing Siberian high located northwest of Lake Baikal (65°N, 100°E) on day −4 slowly moves southeastward, reaches maximum intensity over Siberia (50°N, 110°E) on day 0, and then decays while moving rapidly southward. By contrast, the Aleutian low is almost stagnant and maintains a strong intensity. The eastward pressure gradient geostrophically induces the equatorward cold airmass flux. After day −2, the cold air mass significantly decreases over Siberia, but increases over East Asia and the western North Pacific Ocean. The cold air mass continues to migrate southward while spreading eastward, and disappears mainly over the ocean. The leading edge of the high pressure anomaly moves southward at 13 m s−1 and reaches the equator simultaneously with the equatorward wind anomaly on about day +4. An additional analysis of separating the equatorward flux into 90°–135°E and 135°E–180° suggests that CAOs are, to some extent, caused by the Siberian high and the Aleutian low acting separately.
Mediterranean Tropical-Like Cyclones in Present and Future Climate
Authors: Cavicchia Leone , von Storch Hans , Gualdi Silvio 
Published: August 2014

Abstract
The Mediterranean has been identified as one of the most responsive regions to climate change. It has been conjectured that one of the effects of a warmer climate could be to make the Mediterranean Sea prone to the formation of hurricanes. Already in the present climate regime, however, a few of the numerous low pressure systems that form in the area develop a dynamical evolution similar to the one of tropical cyclones. Even if their spatial extent is generally smaller and the life cycle shorter compared to tropical cyclones, such storms produce severe damage on the highly populated coastal areas surrounding the Mediterranean Sea. This study, based on the analysis of individual realistically simulated storms in homogeneous long-term and high-resolution data from multiple climate change scenarios, shows that the projected effect of climate change on Mediterranean tropical-like cyclones is decreased frequency and a tendency toward a moderate increase of intensity.
Mass-Conserving Remapping of Radar Data onto Two-Dimensional Cartesian Coordinates for Hydrologic Applications
Authors: Sharif Hatim O. , Ogden Fred L. 
Published: August 2014

Abstract
Recent upgrades to operational radar-rainfall products in terms of quality and resolution call for reexamination of the factors that contribute to the uncertainty of radar-rainfall estimation. Remapping or regridding of radar observations onto Cartesian coordinates is implemented by practitioners when radar estimates are compared against rain gauge observations, in hydrologic applications, or for merging data from different radars. However, assuming perfect radar observations, many of the widely used remapping methodologies do not conserve mass for the rainfall rate field. The most popular remapping approaches used are those based on extracting information from radar bins whose centers fall within a certain distance from the center of the Cartesian grid. This paper develops a mass-conserving method for remapping, which is called “precise remapping,” which is compared against two other commonly used remapping methods. Results show that the choice of the remapping method can make a substantial difference in grid-averaged rainfall accumulations (up to more than 100%). Differences were quantified using observations from two radars, collected during a field experiment. The interpolation grid resolution was also found to affect interpolated rainfall estimates. Approximate remapping methods tend to be much more sensitive to the interpolation grid resolution than precise remapping. High-resolution radar data such as those from radars with short gate spacing or narrow beams, or the super-resolution Weather Surveillance Radar-1988 Doppler (WSR-88D) sampling format, are significantly more sensitive (by up to 100%) to the remapping method and the interpolation grid resolution than the legacy WSR-88D rainfall data resolution of 1° × 1 km.
Psychiatric disorders among a sample of internally displaced persons in South Darfur
Authors: Elhabiby Mahmoud M , Radwan Doaa N , Okasha Tarek A , El-Desouky Eman D 
Published: August 2014

Background: The violent armed conflict in Darfur has been ongoing for years getting the attention of human rights activists and mental health professionals. Aim: The aim of this study was to assess psychiatric disorders in a sample of internally displaced persons (IDPs) in South Darfur. Method: A cross-sectional observational study, as a part of the ‘Darfur Campaign’ organized by Arab Federation of Psychiatrists, assessing psychiatric disorders in a sample of internally displaced women using the Structured Clinical Interview for DSM-IV (SCID-I) (clinical version). Results: Up to 25.7% of participants had lost a close family member or more in the violent clashes. Psychiatric diagnoses were found in 62.2% of the participants. The most frequently reported was post-traumatic stress disorder (PTSD) reaching 14.9%, followed by depression 13.5% (among which 2.7% with psychotic features), while comorbid PTSD and depression reached 8.1% of participants. Patients with psychiatric diagnoses had an older age (36.6 years) ( p = .024). Suffering from a psychiatric disorder was found to be associated with losing a family member in the conflict ( p = .015), being 35.6% in patients with psychiatric diagnoses compared to 10.3% in those without losing a family member in the conflict (odds ratio (OR) = 4.7, 95% confidence interval (CI) = 1.25–18.28). Conclusions: This study used a standardized tool for diagnosing psychiatric morbidity among refugees in Darfur to give as much as possible an actual description of the problems and psychiatric morbidity caused by human-made disasters. This study can help to lead to a more detailed and specific mental health service program much needed by this population.
Long-term mental health outcome in post-conflict settings: Similarities and differences between Kosovo and Rwanda
Authors: Eytan Ariel , Munyandamutsa Naasson , Mahoro Nkubamugisha Paul , Gex-Fabry Marianne 
Published: August 2014

Background: Few studies investigated the long-term mental health outcome in culturally different post-conflict settings. This study considers two surveys conducted in Kosovo 8 years after the Balkans war and in Rwanda 14 years after the genocide. Methods: All participants ( n = 864 in Kosovo; n = 962 in Rwanda) were interviewed using the posttraumatic stress disorder (PTSD) and major depressive episode (MDE) sections of the Mini International Neuropsychiatric Interview (MINI) and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Results: Proportions of participants who met diagnostic criteria for either PTSD or MDE were 33.0% in Kosovo and 31.0% in Rwanda, with co-occurrence of both disorders in 17.8% of the Rwandan sample and 9.5% of the Kosovan sample. Among patients with PTSD, patterns of symptoms significantly differed in the two settings, with avoidance and inability to recall less frequent and sense of a foreshortened future and increased startle response more common in Rwanda. Significant differences were also observed in patients with MDE, with loss of energy and difficulties concentrating less frequent and suicidal ideation more common in Rwanda. Comorbid PTSD and MDE were associated with decreased SF-36 subjective mental and physical health scores in both settings, but significantly larger effects in Kosovo than in Rwanda. Conclusion: Culturally different civilian populations exposed to mass trauma may differ with respect to their long-term mental health outcome, including comorbidity, symptom profile and health perception.
Physical phenomena occurring in the process of physical–mechanical degumming of fiber from flax straw
Authors: Konczewicz Wanda 
Published: August 2014

The study presents physical phenomena that occur in the physical–mechanical process of degumming of fiber from flax straw. Moreover, the effect of liquid flow through the straw has been determined by analysis of the mass exchange (motion) according to the principles of fluid mechanics. It was shown that conditions of the degumming process, especially the temperature, have a significant effect on acceleration of the mass exchange. The analyses of the results indicated that the developed model laboratory device allowed for evaluation of the mechanism of mass exchange by slow laminar liquid flow. The evaluation of the degumming process with convective mass motion at a higher speed of liquid flow was based on model tests of hydrodynamic washing of three types of gels: fruit pectin, animal gelatin and starch from linen fabrics. It was shown that temperature is a decisive factor affecting the washing out of gels. Better washing out was achieved by using diffusive penetration of water into the gel structure at the initial phase of the process. Using the dynamic washing out of the gels with a water stream of high flow speed (at the m/s range) shortened considerably the washing time.
The effect of physical factors on the process of physical-mechanical degumming of flax fibers
Authors: Konczewicz Wanda , Wojtysiak Jan 
Published: August 2014

This paper presents results of studies on a new physical-mechanical method of degumming of flax fibers in order to determine optimal parameters of the process for obtaining high-quality fiber. The study was carried out on an experimental device where lengthwise and crosswise flow of the liquid through a straw batch was applied and where the following process parameters were controlled: temperature, flow velocity, and time of the process. The pH was maintained at a stable neutral level. The degumming process was evaluated by measurement of the mass loss of the straw during the process, by physical-chemical tests of the process liquid, by metrological and chemical tests of the obtained fiber, and by statistical analysis of the results. The results of the study, compared with the results of traditional warm water retting, indicate that by proper selection of physical factors of the process, it can be intensified resulting in obtaining high-quality fiber, superior to the fiber obtained in the traditional retting technique.
Constitutional Struggle and Indigenous Resistance in Latin America
Authors: Fisher Eloy 
Published: August 2014

While inequality in Latin America has decreased, being poor and being of indigenous descent are still interchangeable. Uneven progress and policy dereliction with respect to indigenous groups have their consequences: increasingly organized indigenous movements in Latin America struggle today to reclaim and provide new spaces of citizenship around notions of local governance of natural resources and self-determination under harsh social realities. As globalization flattens production and consumption beyond the purview of the traditional nation-state, excluded groups like the indigenous peoples of Latin America have quickly assumed a position of political prominence. Indigenous movements fill the vacuum left by urban groups that today marginally participate in reaping the rewards of higher, commodity-driven growth. In Latin America, indigenous demands have turned into calls for constitutional reform against the interests of governments that wish to develop valuable mineral resources in indigenous regions. However, these indigenous movements are at a crossroads: while instrumental, their situation in political alliances is precarious as governments resort to capital-intensive strategies for the development of resources under their care. Si bien la desigualdad en América Latina ha disminuido, ser pobre y ser de ascendencia indígena aún son intercambiables. Progreso desigual y negligencia en el cumplimiento de políticas con respecto a los grupos indígenas tienen sus consecuencias: los movimientos indígenas cada vez más organizados de América Latina luchan hoy para reclamar y ofrecer nuevos espacios de la ciudadanía acerca de las nociones de gobernabilidad local de los recursos naturales y de la autodeterminación en virtud de las realidades sociales difíciles. Dado que la globalización aplana la producción y el consumo más allá del ámbito de competencia del Estado-nación tradicional, los grupos excluidos, como los pueblos indígenas de América Latina, han asumido rápidamente una posición de prominencia política. Los movimientos indígenas llenan el vacío dejado por los grupos urbanos que hoy participan marginalmente en recoger las recompensas del superior crecimiento del producto impulsado. En América Latina, las demandas indígenas se han convertido en reclamaciones para la reforma constitucional en contra de los intereses de los gobiernos que deseen desarrollar recursos minerales valiosos en las regiones indígenas. Sin embargo, estos movimientos indígenas se encuentran en una encrucijada: si bien instrumental, su situación en las alianzas políticas es precaria ya que los gobiernos recurren a estrategias de uso intensivo de capital para el desarrollo de los recursos bajo su cuidado.
Between the Paternalistic and the Neoliberal State
Authors: Vélez-Torres Irene , Varela Daniel 
Published: August 2014

The sugarcane agro-industry and large-scale mining have generated a profound change in traditional economic practices in the upper Cauca of Colombia to the detriment of the small-scale farmers and miners of the local Afro-descendant population. This has been accompanied by a consolidation of the centralized state since the neoliberal opening and a weakening of the old regional state supported by the paternalistic structure of the agricultural elites. Participative research with two community organizations with regard to the dispute over access to land and environmental assets reveals that the communities and their social organizations have responded to their racialized impoverishment by mobilization and the creation of alliances not only as a means of resistance but also as a strategy for the construction of their own alternative life plans. La agroindustria de caña de azúcar y la minería a gran escala han generado un cambio profundo en las prácticas económicas tradicionales en el Cauca Alto de Colombia, en de-trimento los agricultores y los mineros de pequeña escala de la población afrodescendiente locales. Esto ha sido acompañado por una consolidación del Estado centralizado desde la apertura neoliberal y un debilitamiento del viejo Estado regional apoyado por la estructura paternalista de las elites agrícolas. La investigación participativa con dos organizaciones de la comunidad con respecto a la disputa sobre el acceso a la tierra y los bienes medioambientales revela que las comunidades y sus organizaciones sociales han respondido a su empobrecimiento racializado por la movilización y la creación de alianzas, no sólo como medio de resistencia, pero también como una estrategia para la construcción de sus propios proyectos de vida alternativos.