Investigating the spatial scaling effect of the non-linear hydrological response to precipitation forcing in a physically based land surface model

Precipitation is the most important component and critical to the study of water and energy cycle. In this study we investigated the propagation of precipitation retrieval uncertainty in the simulation of hydrological variables, such as soil moisture, temperature, runoff, and fluxes, for varying spatial resolution on different vegetation cover. Two remotely sensed rain retrievals were explored (one based on satellite IR-only data and the other one based on ground radar data) and three spatial grid resolutions: 0.25°, 0.5° and 1.0°. This investigation was facilitated by an offline Community Land Model (CLM) which is forced by in situ meteorological data from Oklahoma Mesonet and high-resolution (0.1o/hourly) rain gauge-calibrated WSR-88D radar (Nexrad) based precipitation fields. In turn, radar rainfall is replaced by the satellite rain estimates at coarser resolution (0.25°, 0.5° and 1°) to determine their impact on model predictions. A fundamental assumption made in this study is that CLM can adequately represent the physical land surface processes. Results show how uncertainty of precipitation measurement affects the spatial variability of model output in various modelling scales. The study provides some information on the uncertainty of hydrological prediction via interaction between the land surface and near atmosphere fluxes in the modelling approach and hopefully it will contribute to water resource redistribution due to climate change in the Korean Peninsula. Water SA Vol.32 (2) 2006: pp.145-15

Cug2 is essential for normal mitotic control and CNS development in zebrafish.

Background: We recently identified a novel oncogene, Cancer-upregulated gene 2 (CUG2), which is essential for kinetochore formation and promotes tumorigenesis in mammalian cells. However, the in vivo function of CUG2 has not been studied in animal models. Results: To study the function of CUG2 in vivo, we isolated a zebrafish homologue that is expressed specifically in the proliferating cells of the central nervous system (CNS). Morpholino-mediated knockdown of cug2 resulted in apoptosis throughout the CNS and the development of neurodegenerative phenotypes. In addition, cug2-deficient embryos contained mitotically arrested cells displaying abnormal spindle formation and chromosome misalignment in the neural plate. Conclusions: Therefore, our findings suggest that Cug2 is required for normal mitosis during early neurogenesis and has functions in neuronal cell maintenance, thus demonstrating that the cug2 deficient embryos may provide a model system for human neurodegenerative disorders

Interactions of B = 4 Skyrmions

It is known that the interactions of single Skyrmions are asymptotically described by a Yukawa dipole potential. Less is known about the interactions of solutions of the Skyrme model with higher baryon number. In this paper, it is shown that Yukawa multipole theory can be more generally applied to Skyrmion interactions, and in particular to the long-range dominant interactions of the B = 4 solution of the Skyrme model, which models the alpha-particle. A method that gives the quadrupole nature of the interaction a more intuitive meaning in the pion field colour picture is demonstrated. Numerical methods are employed to find the precise strength of quadrupole and octupole interactions. The results are applied to the B = 8 and B = 12 solutions and to the Skyrme crystal.Comment: 21 pages, 11 figure

An unexpected journey of a suction catheter in a preterm neonate

Foreign bodies are extremely rare in preterm neonates. The majority are iatrogenic. We describe a neonate of 27 weeks gestation who was found to have an 18 mm long suction catheter at the right main bronchi after resuscitation in another hospital. It was first detected by chest X-ray after endotracheal intubation. Repeat X-ray revealed the catheter moved to the stomach and migrated to the lower gastrointestinal tract in a few hours. The patient was treated conservatively and the catheter was passed out on day 14. Newborn resuscitation may result in iatrogenic foreign body in neonates. Serious complications such as respiratory compromise, perforations or abscess may occur. Early referral to a specialized tertiary center with pediatric surgical service is recommended. We hope our experience demonstrated the importance of preventing iatrogenic foreign body in clinical setting. Access to endoscopic instrumentation for foreign body removal in preterm neonates should be available at all times.published_or_final_versio

Management and outcome of antenatally diagnosed congenital cystic adenomatoid malformation of the lung

Objective: To review the management and outcome of babies with antenatally diagnosed congenital cystic adenomatoid malformation. Design: Retrospective cohort review. Setting: Tertiary neonatal care unit at Queen Mary Hospital and antenatal diagnostic centre at Tsan Yuk Hospital. Patients: Consecutive patients with antenatally suspected congenital cystic adenomatoid malformation in their concepti among antenatal patients attending Tsan Yuk Hospital from 1994 to 2002. Twenty-four of 33 cases were referred to Queen Mary Hospital for postnatal management and for whom comprehensive records were available for analysis in 23. Interventions: Postnatal interventions in their babies included investigational imaging for congenital cystic adenomatoid malformation and surgery. Main outcome measures: Antenatal and postnatal outcome, as well as pathology of the excised lesions. Results: Antenatal outcome: termination of pregnancy in two cases and spontaneous abortion in one; in-utero regression was documented in nine cases and in one hydropic change was apparent. Postnatal outcome: only eight of 20 babies born alive had symptoms in neonatal period. Two developed serious infective complications in infancy, one with documented in-utero regression. Pulmonary parenchymal abnormalities were detected on computed tomography of the thorax in six of seven cases with normal or non-specific chest radiograph findings. Among nine cases with in-utero regression, congenital cystic adenomatoid malformation was confirmed by operative histology in five and abnormal computed tomography findings in three. Fifteen babies underwent surgical excision, one of whom died because of severe pre-existing pulmonary hypoplasia and nine endured minor postoperative complications. A favourable outcome was documented at a mean follow-up of 22 months (range, 2 months-7 years). Conclusions: In-utero regression of congenital cystic adenomatoid malformation on antenatal ultrasound may not represent genuine resolution. Computed tomographic thorax should be considered in all newborns with antenatally diagnosed congenital cystic adenomatoid malformation, and if confirmed early operation before first hospital discharge is recommended.published_or_final_versio

Animal models of cancer biology

Introductory Editorialpublished_or_final_versio

Reversible posterior leukoencephalopathy syndrome in Chinese children induced by chemotherapy: A review of five cases

This is a retrospective review of the clinico-radiological features and neurological outcomes of reversible posterior leukoencephalopathy syndrome episodes in Chinese cancer children receiving chemotherapy in a regional hospital in Hong Kong from 1998 to 2008. Five children (3 males and 2 females) with a mean age of 7 years were identified, four of whom had acute lymphoblastic leukaemia and one had a central nervous system germ cell tumour. Presenting symptoms included seizures (100%), altered mental function (100%), headache (40%), and visual disturbance (60%). The mean systolic blood pressure at presentation was 158 mm Hg. Approximately 80% had typical radiological features of reversible posterior leukoencephalopathy syndrome. All showed complete recovery after the acute stage, but one subsequently developed epilepsy. Two patients ultimately died of refractory malignant disease. Two others were followed up for a mean of 6 years, and remained neurologically normal. This report was the first case review documenting reversible posterior leukoencephalopathy syndrome in Chinese cancer children. The clinico-radiological features and neurological outcomes were similar to those reported in western series. Early recognition of the syndrome is important to facilitate appropriate treatment. The central nervous system damage may not be reversible and thus long-term follow-up is warranted.published_or_final_versio

Genome-wide diel growth state transitions in the diatom Thalassiosira pseudonana

Marine diatoms are important primary producers that thrive in diverse and dynamic environments. They do so, in theory, by sensing changing conditions and adapting their physiology accordingly. Using the model species Thalassiosira pseudonana, we conducted a detailed physiological and transcriptomic survey to measure the recurrent transcriptional changes that characterize typical diatom growth in batch culture. Roughly 40% of the transcriptome varied significantly and recurrently, reflecting large, reproducible cell-state transitions between four principal states: (i) "dawn," following 12 h of darkness; (ii ) "dusk," following 12 h of light; (iii ) exponential growth and nutrient repletion; and (iv) stationary phase and nutrient depletion. Increases in expression of thousands of genes at the end of the reoccurring dark periods (dawn), including those involved in photosynthesis (e.g., ribulose-1,5- bisphosphate carboxylase oxygenase genes rbcS and rbcL), imply large-scale anticipatory circadian mechanisms at the level of gene regulation. Repeated shifts in the transcript levels of hundreds of genes encoding sensory, signaling, and regulatory functions accompanied the four cell-state transitions, providing a preliminary map of the highly coordinated gene regulatory program under varying conditions. Several putative light sensing and signaling proteins were associated with recurrent diel transitions, suggesting that these genes may be involved in light-sensitive and circadian regulation of cell state. These results begin to explain, in comprehensive detail, how the diatom gene regulatory program operates under varying environmental conditions. Detailed knowledge of this dynamic molecular process will be invaluable for new hypothesis generation and the interpretation of genetic, environmental, and metatranscriptomic data from field studies

Impact of respiratory muscle training on respiratory muscle strength, respiratory function and quality of life in individuals with tetraplegia: A randomised clinical trial

Background Respiratory complications remain a leading cause of morbidity and mortality in people with acute and chronic tetraplegia. Respiratory muscle weakness following spinal cord injury-induced tetraplegia impairs lung function and the ability to cough. In particular, inspiratory muscle strength has been identified as the best predictor of the likelihood of developing pneumonia in individuals with tetraplegia. We hypothesised that 6 weeks of progressive respiratory muscle training (RMT) increases respiratory muscle strength with improvements in lung function, quality of life and respiratory health. Methods Sixty-two adults with tetraplegia participated in a double-blind randomised controlled trial. Active or sham RMT was performed twice daily for 6 weeks. Inspiratory muscle strength, measured as maximal inspiratory pressure (PImax) was the primary outcome. Secondary outcomes included lung function, quality of life and respiratory health. Between-group comparisons were obtained with linear models adjusting for baseline values of the outcomes. Results After 6 weeks, there was a greater improvement in PImax in the active group than in the sham group (mean difference 11.5 cmH 2 O (95% CI 5.6 to 17.4), p<0.001) and respiratory symptoms were reduced (St George Respiratory Questionnaire mean difference 10.3 points (0.01-20.65), p=0.046). Significant improvements were observed in quality of life (EuroQol-Five Dimensional Visual Analogue Scale 14.9 points (1.9-27.9), p=0.023) and perceived breathlessness (Borg score 0.64 (0.11-1.17), p=0.021). There were no significant improvements in other measures of respiratory function (p=0.126-0.979). Conclusions Progressive RMT increases inspiratory muscle strength in people with tetraplegia, by a magnitude which is likely to be clinically significant. Measurement of baseline PImax and provision of RMT to at-risk individuals may reduce respiratory complications after tetraplegia. Trial registration number Australian New Zealand Clinical Trials Registry (ACTRN 12612000929808)