Armonización de calendarios en el mundo islámico primitivo como se refleja en Elementos de astronomía de al-Farghānī

This paper seeks to shed more light on calendrical knowledge in the first centuries of the Islamic era in which different administrative traditions fell under the control of a central government. Astronomy as a court-sponsored discipline in the Abbasid dynasty (132-656 AH/750-1258 CE), undertook the pivotal task of identifying and mastering various calendrical disciplines under the reign of the caliphs to make a centralized management feasible. In the first two centuries, the domination of the Arabic lunar calendar, whose significance lies in governing the Islamic yearly festivals and occasions, led to drastic disagreements with the annual planting cycles that were followed by the farmers. Accordingly, the official taxation system faced serious problems. The solution to which was the development of a well-established solar calendar. The large concern of the ninth-century Muslim astronomers for calendrical computations, acknowledges their integral participation in this executive challenge. The present study follows these practices through the lens of a ninth-century Arabic astronomical text, written by Aḥmad b. Muḥammad b. Kathīr al-Farghānī (Alfraganus in the west), known mainly as the Elements of Astronomy. The careful exploration of this text helps us achieve a broader image of time-keeping accounts in the early Islamic era and the need for calendrical conversions. Moreover, the author’s detailed report of the five existing calendars of the time (Arabic, Syriac, Byzantine, Persian and Egyptian) and their systems of nomenclature, opens an early window to the linguistic investigation of time-reckoning in the Islamic world. Este artículo pretende arrojar luz sobre los conocimientos calendáricos en los primeros siglos de la era islámica, en los que diferentes tradiciones administrativas quedaban bajo el control de un gobierno central. La astronomía, como disciplina patrocinada por la corte en la dinastía abasí (132-656 /750-1258), emprendió la tarea fundamental de identificar y dominar varias disciplinas calendáricas bajo el reinado de los califas para hacer viable una gestión centralizada. En los dos primeros siglos, el dominio del calendario lunar árabe, cuya importancia radica en la regulación de las fiestas y ocasiones anuales islámicas, provocó drásticos desacuerdos con los ciclos anuales de siembra que seguían los agricultores. En consecuencia, el sistema fiscal oficial se enfrentó a graves problemas, cuya solución fue el desarrollo de un calendario solar bien establecido. La gran preocupación de los astrónomos musulmanes del siglo IX por los cómputos calendáricos reconoce su participación integral en este desafío ejecutivo. El presente estudio sigue estas prácticas a través de la atenta lectura de un texto astronómico árabe del siglo IX escrito por Ahmad b. Muhammad b. Kathīr al-Farghānī (Alfraganus en occidente), conocido principalmente como los Elementos de Astronomía. La cuidadosa exploración de este texto nos ayuda a conseguir una imagen más amplia de los relatos sobre el tiempo en la primera época islámica y la necesidad de las conversiones calendáricas. Además, el informe detallado del autor sobre los cinco calendarios existentes en la época (árabe, siríaco, bizantino, persa y egipcio) y sus sistemas de nomenclatura, abre una posibilidad para la investigación lingüística de la relojería en el mundo islámico.

Statistical inference in population genomics

The field of population genomics has grown rapidly with the recent advent of affordable, large-scale sequencing technologies. As opposed to the situation during the majority of the 20th century, in which the development of theoretical and statistical population-genetic insights out-paced the generation of data to which they could be applied, genomic data are now being produced at a far greater rate than they can be meaningfully analyzed and interpreted. With this wealth of data has come a tendency to focus on fitting specific (and often rather idiosyncratic) models to data, at the expense of a careful exploration of the range of possible underlying evolutionary processes. For example, the approach of directly investigating models of adaptive evolution in each newly sequenced population or species often neglects the fact that a thorough characterization of ubiquitous non-adaptive processes is a prerequisite for accurate inference. We here describe the perils of these tendencies, present our views on current best practices in population genomic data analysis, and highlight areas of statistical inference and theory that are in need of further attention. Thereby, we argue for the importance of defining a biologically relevant baseline model tuned to the details of each new analysis, of skepticism and scrutiny in interpreting model-fitting results, and of carefully defining addressable hypotheses and underlying uncertainties.

On the Importance of Considering Multinuclear Metal Sites in Homogeneous Catalysis Modeling

In this short review, we provide an account of a number of computational studies of catalytic reaction mechanisms carried out in our groups. We focus in particular on studies in which we came to realize during the course of the investigation that the active catalytic species was a bimetallic complex, rather a monometallic one as previously assumed. In some cases, this realization was in part prompted by experimental observations, but careful exploration based on computation of the speciation of the metal precursor also provided a powerful guide: it is often possible to predict that bimetallic species (intermediates or transition states) lie lower in free energy than a priori competitive monometallic species. In this sense, we argue that in organometallic catalysis, the rule whereby “two is better than one” turns out to be relevant much more often than one might expect.

Surmounting Stereotyping of International Students

This study attempted to investigate the experiences of international students towards stereotyping inside and outside of the campus. The purpose of this study was to explore the students’ experiences on stereotyping and employed qualitative method as the mode of inquiry. Semi-structured interview was conducted with five postgraduates’ students in one of the public universities in Malaysia. The respondents came from different countries and majors of studies. Finding from the study found that international students did experience stereotyping, but this encounter seemed not to affect their studies. Finally, future researchers are encouraged to adapt this study within a larger group of respondents to examine its confirmability and credibility. A careful exploration of stereotype in the areas of intercultural and cross-cultural communication among international students may provide more insights into their wellbeing in countries away from home.

Studies in the vascular flora of the southeastern United States. VII

As part of ongoing efforts to understand, document, and conserve the flora of southeastern North America, we propose two new species, the recognition of a usually synonymized variety, the acceptance of two species of Waltheria as being present in peninsular Florida, taxonomic acceptance of a sometimes deprecated species transferred with a new name into a different genus, and we clarify the distribution and ecology of a species. In Carex (Cyperaceae), we re-analyze infrataxa in Carex intumescens and recommend the recognition of two varieties, a taxonomic schema first proposed in 1893, but usually not followed in the 128 years since. In Euphorbia (Euphorbiaceae), a careful assessment of south Florida material of Euphorbia subg. Chamaesyce sect. Anisophyllum subsect. Hypericifoliae reveals the need for taxonomic changes to best classify endemic representatives of this group, resulting in the naming of a new species, and a new name at species rank in Euphorbia for a taxon first named in Chamaesyce and sometimes subsequently treated at only varietal rank in Euphorbia. Chamaecrista deeringiana (Fabaceae, subfamily Caesalpinioideae) has been repeatedly misinterpreted to include two different and disjunct population systems with differing morphologies and habitats, which are here interpreted as separate species, one newly named and the other Chamaecrista deeringiana returned to its original and narrower interpretation as a south Florida endemic. Waltheria (Malvaceae) has sometimes been interpreted as being represented in Florida by a single taxon, Waltheria indica, but we disentangle the concepts of the widespread W. indica and the West Indian W. bahamensis and clarify that both are present in the southeastern United States. We reconsider the occurrence and habitat of Toxicoscordion nuttallii (Melanthiaceae) in three states in which it has been reported as a rare species, Mississippi, Missouri, and Louisiana, and remove it from the Mississippi flora as a garbled and false report. In Louisiana, its occurrence in calcareous prairie complexes limits its potential occurrence in the state to a specialized and rare habitat, but careful exploration of habitat remnants may result in the discovery of additional populations. Taxonomic studies and re-assessments of this kind are critical in laying the best scientific foundation for regulatory, policy, and land conservation decisions. This paper names or makes the case for the renewed acceptance of six species with range-wide conservation concern: one Critically Imperiled (G1 – Euphorbia ogdenii), one Imperiled (G2 – E. hammeri), and four Vulnerable (G3 – E. garberi, E. porteriana, Chamaecrista deeringiana, C. horizontalis).

Diagnosis and Surgical Principles in the Treatment of Acute Injuries of the Flexor Tendons of the Hand

Injuries to the flexor tendons of the wrist are a separate chapter in wrist surgery. Flexor tendon injuries still remain a challenge to ensure the patient's optimal outcome. A special problem in the exploration of hand injuries is the accurate assessment of whether there is an injury to one or more tendons, at what height the injury is, and whether it is accompanied by injury to other elements of the hand. On the volar side of the hand, both flexors of the fingers, superficial and deep, or just one of them, maybe injured. If the lesion is in the first zone depending on the severity of the injury, reinsertion or direct tenography is required. In the second zone, there are still ambiguous views on the reconstruction of the deep and superficial flexor, ie. whether the surface flexor needs to be reconstructed. Injury to the flexor tendons in the third zone requires careful exploration for possible injury to the neurovascular elements, and the fourth zone often requires the release of the carpal tunnel. In the most proximal zone of the flexor tendons, the fifth zone, injury to the main blood vessels of the hand and the nerves responsible for sensitive and motor innervation of the hand is possible. Each injury should be approached with careful preoperative examination, appropriate operative technique as well as postoperative rehabilitation in order to fully restore the function of the hand.

Reorganization of Resting-State EEG Functional Connectivity Patterns in Children with Cerebral Palsy Following a Motor Imagery Virtual-Reality Intervention

Motor imagery (MI) has been suggested to provide additional benefits when included in traditional approaches of physical therapy for children with cerebral palsy (CP). Regardless, little is understood about the underlying neurological substrates that might justify its supposed benefits. In this work, we studied resting-state (RS) electroencephalography (EEG) recordings of five children with CP that underwent a MI virtual-reality (VR) intervention. Our aim was to explore functional connectivity (FC) patterns alterations following this intervention through the formalism of graph theory, performing both group and subject-specific analyses. We found that FC patterns were more consistent across subjects prior to the MI-VR intervention, shifting along the anterior-posterior axis, post-intervention, for the β and γ bands. Additionally, group FC patterns were not found for the α range. Furthermore, intra-subject analyses reinforced the existence of large inter-subject variability and the need for a careful exploration of individual pattern alterations. Such patterns also hinted at a dependency between short-term functional plasticity mechanisms and the EEG frequency bands. Although our sample size is small, we provide a longitudinal analysis framework that can be replicated in future studies, especially at the group level, and whose foundation can be easily extended to verify the validity of our hypotheses.

PTSD Treatment Problems at the U.S. Veterans Administration

Post-traumatic stress disorder (PTSD) increasingly burdens the health of many people, as indicated by the growing numbers of U.S. military veterans’ claims. An increased awareness of PTSD as a health concern necessitates a careful exploration of treatments. A range of current PTSD treatments and the need to more selectively utilize treatments is addressed. Studies indicate that recent PTSD treatment breakthroughs may offer promise and can be more effectively utilized. Assertions from organizations such as the U.S. National Center for PTSD contradict the commonly cited contention that there is no “cure” for PTSD. A review of PTSD literature reveals that: (1) the U.S. Veterans Administration is dispensing drugs (some of which have harmful side effects) that are not approved for use in treating PTSD by the U.S. Food and Drug Administration, (2) not aggressively exploring the use of novel approaches to PTSD treatment, and (3) not adequately funding research into PTSD treatment relatively to the funding of disability payments. Because of these factors the U.S. government is not optimally serving the interests of veterans.

Prevalence and Distribution of the Middle Mesial Canal in Mandibular First Molar Teeth of the Kerman Population: A CBCT Study

Purpose. Missed additional canals are one of the most important reasons for RCT failures in molar teeth. This study aimed to determine the prevalence and distribution of middle mesial canals in mandibular first molars of the Kerman population. Materials and Methods. A retrospective study was performed on de-identified cone beam image sets from 3 private radiology centers in Kerman. A total of 100 mandibular first molars from 62 patients (mean age 32 years) were included. Information regarding the patient’s age and gender, the location of teeth, and the presence or absence of a MMC and also a second distal canal in MMC cases was recorded in an Excel table. Data were analyzed using SPSS software (IBM-USA). Results. The overall prevalence of MMCs in the mandibular first molars was 8.1% (10.0% in females and 6.3% in males). More cases of MMCs were seen on the right side (12.2%) than the left side (3.4%). One case of bilateral MMCs combined with bilateral second distal canals in the mandibular first molars was seen in a 26-year-old female. A further case of bilateral MMCs was found in a 32-year-old male but with single-canal distal roots on both sides. Conclusion. The overall prevalence of MMCs in the Kerman population (8.1%) is at the lower end of the reported range of the international literature (0.26% to 53.8%). In the cohort examined in this study, mid mesial canals were more prevalent in females and on the right side. There was no definite relationship between MMCs and second distal canals in the mandibular first molar teeth in the same subject. MMCs may be unilateral or bilateral. Careful exploration of the pulpal floor between canal orifices is essential to prevent missing the MMC, as this would cause undesirable clinical outcomes.

Pet dog bites in children: management and prevention

Dog bite injuries are a significant public health problem and many are sustained by children. These injuries can be complex, both physically and psychologically, and in rare cases fatal. This paper will review current evidence-based approaches to treatment, explore identified patterns in biting incidents and discuss the effectiveness of prevention strategies. Safe management of these patients requires a comprehensive approach. Physical injuries need to be accurately assessed with a high index of suspicion for underlying injuries, particularly in younger children less able to communicate. Treatment depends on severity and location, but all bites must be irrigated to reduce the risk of infection but may not always require prophylactic antibiotic use. Careful exploration of the circumstances in which the bite occurred is essential to make safeguarding decisions and prevent future bites. Reducing the incidence of paediatric dog bites requires education of both children and parents that any dog can bite, regardless of breed, and all child–dog interactions must be highly supervised. However, education alone is unlikely to prevent dog bites. Policies that support environmental changes need to be developed such as provision of pet dogs less likely to bite (or bite as severely), through breeding for temperament and appropriate socialisation. Additionally, investment in psychological support for bite victims and their families is required to reduce the long-term impacts of being bitten.