Modeling Of Invasive Exotic Plants Dynamics in Arid Region Using Remote Sensing and GIS: A Case Study of Prosopis Juliflora in the UAE

High resolution digital aerial photographs were used to rate the change and to evaluate the woody Prosopis juliflora dynamics in northern UAE, Filayah (untreated) and Khut (treated). A time series of three different dates: 1986, 1996, and 2005 were chosen. Onscreen digitizing of plant communities was conducted using interpretative elements such as shape, tone texture, shadow and final maps were produced with acceptable accuracy. A geodatabase was built for both sites containing layers representing different dates. Statistical analysis was performed to rate the changes of the following four spatial attributes: percent cover, patch density, patch size, and mean patch shape index. GIS Overlay analysis was conducted to visualize plant dynamics and find possible spatial associations. Results showed that Prosopis juliflora represents a real threat to the local native species, as its percent cover increased during 19-years study period (1986-2005), from 10.48 to 16.17% in Filayah area, and from 1.19 to 32.48% in Khut area. Furthermore, patch density was also continuously increasing during the study period as it increased from 2.8 to 5.96 patch/ha for Filayah area, and from 1.58 to 25.05 patch/ha in Khut area during the same period. It seems that P. juliflora goes through phases of expansion. First, an accelerated expansion earlier in the establishment period, and then the distribution reaches a plateau. This plateau may be an optimum density of P. juliflora in that region. The time period for such optimum is suggested to be around 10 years from invasion

NsrR from Streptomyces coelicolor is a nitric oxide-sensing [4Fe-4S] cluster protein with a specialized regulatory function

The Rrf2 family transcription factor NsrR controls expression of genes in a wide range of bacteria in response to nitric oxide (NO). The precise form of the NO-sensing module of NsrR is the subject of controversy because NsrR proteins containing either [2Fe-2S] or [4Fe-4S] clusters have been observed previously. Optical, Mössbauer, resonance Raman spectroscopies and native mass spectrometry demonstrate that Streptomyces coelicolor NsrR (ScNsrR), previously reported to contain a [2Fe-2S] cluster, can be isolated containing a [4Fe-4S] cluster. ChIP-seq experiments indicated that the ScNsrR regulon is small, consisting of only hmpA1, hmpA2, and nsrR itself. The hmpA genes encode NO-detoxifying flavohemoglobins, indicating that ScNsrR has a specialized regulatory function focused on NO detoxification and is not a global regulator like some NsrR orthologues. EMSAs and DNase I footprinting showed that the [4Fe-4S] form of ScNsrR binds specifically and tightly to an 11-bp inverted repeat sequence in the promoter regions of the identified target genes and that DNA binding is abolished following reaction with NO. Resonance Raman data were consistent with cluster coordination by three Cys residues and one oxygen-containing residue, and analysis of ScNsrR variants suggested that highly conserved Glu-85 may be the fourth ligand. Finally, we demonstrate that some low molecular weight thiols, but importantly not physiologically relevant thiols, such as cysteine and an analogue of mycothiol, bind weakly to the [4Fe-4S] cluster, and exposure of this bound form to O2 results in cluster conversion to the [2Fe-2S] form, which does not bind to DNA. These data help to account for the observation of [2Fe-2S] forms of NsrR

Performance of Combined PCM/Metal Foam-based Photovoltaic Thermal (PVT) Collector

Photovoltaic thermal collector (PVT) is a power generation technology that adapts solar radiation into electrical and thermal energy. There are two cooling methods in PV panels: active and passive. Phase Change Materials (PCM) have high latent heat during charging and discharging, making them promising as thermal energy storage. However, their low thermal conductivity remains a major drawback, which was to be solved by porous metal foams given their high thermal conductivity, low density, and lightness. This study aimed to introduce and analyze a novel PVT design by integrating PCM with Copper Foam Matrix (CFM) as passive cooling combined with submerged serpentine copper tubes for fluid flow as active cooling. This novel PVT was run with and without CFM by conducting a 3D steady-state simulation using COMSOL Multiphysics. This study showed that incorporating the PCM plus CFM will decrease the PV surface temperature and increase electrical efficiency. The effective thermal conductivity of PCM increased, leading to higher thermal extraction at the tested mass flow rates. At an irradiance of 1000W/m2 and an ambient temperature of 20˚C, the collector achieved 65% and 13% thermal and electrical efficiency, respectively

MAP4 Mechanism that Stabilizes Mitochondrial Permeability Transition in Hypoxia: Microtubule Enhancement and DYNLT1 Interaction with VDAC1

Mitochondrial membrane permeability has received considerable attention recently because of its key role in apoptosis and necrosis induced by physiological events such as hypoxia. The manner in which mitochondria interact with other molecules to regulate mitochondrial permeability and cell destiny remains elusive. Previously we verified that hypoxia-induced phosphorylation of microtubule-associated protein 4 (MAP4) could lead to microtubules (MTs) disruption. In this study, we established the hypoxic (1% O2) cell models of rat cardiomyocytes, H9c2 and HeLa cells to further test MAP4 function. We demonstrated that increase in the pool of MAP4 could promote the stabilization of MT networks by increasing the synthesis and polymerization of tubulin in hypoxia. Results showed MAP4 overexpression could enhance cell viability and ATP content under hypoxic conditions. Subsequently we employed a yeast two-hybrid system to tag a protein interacting with mitochondria, dynein light chain Tctex-type 1 (DYNLT1), by hVDAC1 bait. We confirmed that DYNLT1 had protein-protein interactions with voltage-dependent anion channel 1 (VDAC1) using co-immunoprecipitation; and immunofluorescence technique showed that DYNLT1 was closely associated with MTs and VDAC1. Furthermore, DYNLT1 interactions with MAP4 were explored using a knockdown technique. We thus propose two possible mechanisms triggered by MAP4: (1) stabilization of MT networks, (2) DYNLT1 modulation, which is connected with VDAC1, and inhibition of hypoxia-induced mitochondrial permeabilization

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Pediatric versus adult kidney transplantation activity in Arab countries

The objective of this study was to evaluate the current activity of pediatric versus adult kidney transplantation activity in the Arab world. A questionnaire was mailed to all kidney transplant centers in Arab countries to collect data on the kidney transplant activity in a recent single year. Three thousand three hundred and nine kidney transplants were performed in one year, with a transplant rate of 9.5 per million populations (PMP); 298 were performed for children with a pediatric kidney transplant (PKT) rate of 0.87 PMP, which is much lower than that of developed countries where it mostly ranges from 5 to 10. The pediatric share of all transplants is 9%, which is twice as high as that of European children. Kidney transplant programs in most Arab countries rely exclusively on living donors as there is a severe shortage of deceased donors. 93.5% of all transplants, combined adult and pediatric, were from living donors. Deceased transplant activity in Arab countries accounts for 14-31% of all transplants in the three countries with deceased donor programs. Of the 212 adult and pediatric transplants that were performed from deceased donors in eight countries, only 29 cases were for pediatric recipients. Deceased PKT is available in the Kingdom of Saudi Arabia (KSA), Tunisia and Kuwait. Surprisingly, the PKT share was not better in the countries with higher overall kidney transplant rate and or in those where deceased transplant was available. PKT is still inactive in most Arab countries and mostly relies on living donors. The lack of well-developed deceased donor programs is the main issue to be addressed

MESOT Fellowship Program

The MESOT (Middle East Society for Organ Transplantation) is pleased to announce theMESOT Fellowship Program for the year 2010. This program has been established in 2008 for physicians and surgeons from the Middle East region willing to acquire some particular skills related to various aspects of organ transplantation in several centers of excellence from around the Middle East. The objective of this program is to promote and advance organ transplantation in underserved areas of this region of the world by helping them to establish local transplant programsor to improve an existing program. A limited number of grants are available for the time being. Application form is available in the MESOT website: www.mesot-tx.orgApplication deadline is the 30th of June, 2010. Any individual interested in this training program should direct his or her inquiries to the chairman of The MESOT Fellowship Program Committee

دراسة ومحاكاة الضخ الشمسي لليزر Nd: YAG باستخدام برنامج ZEMAX

يتضمن البحث دراسة طرق تركيز وتجميع الاشعاع الشمسي للحصول على طاقة الضخ الضوئي المناسبة لليزر Nd: YAG. وتم اعتماد نظام تركيز شمسي مؤلف من مرآة مستوية مساحتها 1m2 ومركز ذو قطع مكافئ قطره 1.8m من أجل تركيز الاشعاع الشمسي على المادة الفعّالة لليزر وتوصلنا بهذه العملية إلى كفاءة تركيز بلغت 89%.     تم أيضاً نمذجة ومحاكاة النظام المقترح أعلاه بطريقتين للضخ (الجانبي، والطرفي) لقضيب Nd: YAG باستخدام برنامج Zemax والمقارنة بين كفاءتيهما حيث بلغت كفاءة امتصاص القضيب لطاقة الضخ الفعالة المركزة 80% في نظام الضخ الطرفي بينما بلغت 63% في نظام الضخ الجانبي