Detection of canine parvovirus type 2c (CPV-2c) in Palestine.

INTRODUCTION: The objective of the present study was to report, for the first time, the presence of canine parvovirus type 2c (CPV-2c) in domesticated dogs with acute gastroenteritis and to characterize the antigenic variants circulating in Palestine. METHODOLOGY: A veterinary clinical-based epidemiological study was carried out between December 2022 and April 2023. Fifty fecal samples were collected from dogs with gastroenteritis and screened for CPV-2 infection by polymerase chain reaction. The distribution of positive cases according to various epidemiological factors was studied. Partial sequencing of the viral protein 2 (VP2) gene was performed for the analysis of CPV-2 variants. RESULTS: Most of the investigated samples (60%; n = 50) during the study period were found positive for CPV-2 infection. There was no difference in the distribution of positive cases of CPV-2 infection based on age group, gender, location, and vaccination status. The analysis of nucleotide and amino acid sequences from amplified products, as well as phylogenetic analysis, revealed the presence of CPV-2c clustered with Asian CPV-2c variants. CONCLUSIONS: In summary, this study represents the initial genetic analysis of CPV-2 present in Palestinian dogs with gastroenteritis and provides evidence that confirms the existence of the CPV-2c variants. To determine the prevailing CPV-2 variant associated with the infection, it is crucial to conduct further sequence analysis using large populations of both domestic and wild canines.

First report of mobile colistin resistance gene mcr-1 in avian pathogenic Escherichia coli isolated from turkeys in the Gaza Strip, Palestine.

Background and Aim: Colistin is used to treat avian pathogenic Escherichia coli (APEC), a microorganism that affects turkey meat production in the Gaza Strip and worldwide. However, the recent emergence of plasmid-borne mobile colistin resistance (mcr) genes in pathogenic E. coli strains is a serious antimicrobial resistance (AMR) challenge for both human and animal health. In December 2018, colistin was banned as a veterinary antimicrobial in the Gaza Strip. This study aimed to detect and track the prevalence of colistin-resistant APEC isolated from turkey flocks in the Gaza Strip. Materials and Methods: This study investigated 239 APEC isolates from turkey flocks in the Gaza Strip between October 2018 and December 2021 (at 6-month intervals). The colistin-resistant APEC strains were detected using the broth microdilution method. The mcr-1 gene was identified using a polymerase chain reaction. Results: The overall colistin resistance among the isolated APECs was 32.2% during the study period. The average resistance in the first interval was 37.5%, which significantly decreased to 9.3% in the last interval. Among the 77 phenotypically resistant isolates, 32.4% were positive for mcr-1. The average abundance of mcr-1 in the first interval was 66.6%, which decreased to 25% in the last interval. Conclusion: To the best of our knowledge, this is the first study reporting the presence of the mcr-1 gene among the APEC isolates from turkeys in the Gaza Strip. Banned veterinary use of colistin significantly decreased the percentage of resistant APEC isolates from turkeys in Gaza Strip. Further studies are needed to investigate other colistin resistance genes and track the emergence of AMR.

Occurrence and phylogenetic analysis of fowl adenovirus E in broiler flocks from Gaza Strip Palestine.

INTRODUCTION: Inclusion-body hepatitis (IBH) and hydropericardium syndrome (HPS) are highly infectious diseases caused by fowl adenoviruses (FAdVs). IBH and HPS cause major economic losses in poultry production. IBH is caused by multiple FAdV serotypes such as FAdV-11, FAdV8a, and FAdV8b; while HPS is mainly caused by the FAdV-4 serotype. In 2018, we detected FAdVs in West Bank - Palestine for the first time. This study aims to monitor the emergence of new FAdVs in broiler farms in Gaza Strip-Palestine in 2022. METHODOLOGY: The clinical signs, necropsy, and histopathological findings associated with IBH in the suspected birds were recorded. Polymerase chain reaction (PCR) was performed using primers matching the virus-encoded L1 loop of the hexon gene. The sequences of the L1 loop were analyzed and a phylogenetic tree was constructed and compared with the related FAdV field isolates and reference strains from different regions of the world available in GenBank. RESULTS: The infected broiler displayed FAdVs-induced clinical symptoms and pathological lesions with mortality rates ranging from 20-46%. The L1 loop sequences from the infected flocks were submitted to GenBank with accession numbers ON638995, ON872150, and ON872151. The identified L1 loop gene has high nucleotide homology (96.7-97.9%) to the highly pathogenic FAdV E serotype 8b strain FAdV_isolate_04-53357-122_Canada_2007 (GenBank: EF685489) and 94.5-94.6% to FAdV_10_Belgium_2010 isolate 11-15941 (GenBank: AF339924.1). Furthermore, the phylogenetic analysis indicated that they belong to FAdV-E serotype 8b. CONCLUSIONS: Our study reports the emergence of FAdV-E causing IBH disease in broiler chickens for the first time in Gaza in Palestine.

Facilitation by Haloxylon persicum Shrubs Enhances Density and Richness of Soil Seed Bank of Annual Plants in a Hyper-Arid Ecosystem.

The soil seed bank is an essential functional component of plant communities. In arid ecosystems, the island-like distribution of shrubs influences the spatial distribution of the soil seed bank. Very little is known about seed banks in deserts of the Middle East. The present study aimed to evaluate the facilitative effects of Haloxylon persicum shrubs on the soil seed bank of annual plants in a sandy desert region in northwestern Saudi Arabia during two consecutive growing seasons (2017-2018 and 2018-2019) with contrasting rainfall. A total of 480 soil samples at 12 stands were collected from two microhabitats, under shrubs and in open areas, soon after the two growing seasons. The germinable seed bank of annual plants was estimated by controlled seedling emergence method. Shrubs significantly facilitated the accumulation of seed bank beneath their canopies after the two growing seasons. In both microhabitats, the size and species richness of soil seed bank were significantly greater after the wet growing season (2018-2019) than following the dry season (2017-2018). The facilitative effects of shrubs were greater following the moister growing season than after the dry season. The effect of shrubs on seed bank-annual vegetation similarity varied between growing seasons, being greater in shrub interspaces than beneath shrub canopies for the dry growing season, while during the wet season, the similarity of the seed bank with standing annual vegetation was greater in sub-canopy microhabitat than in bare soil.

Association of SARC-F Score and Rockwood Clinical Frailty Scale with CT-Derived Muscle Mass in Patients with Aortic Aneurysms.

OBJECTIVES: Patients with aortic aneurysms (AA) are often co-morbid and susceptible to frailty. Low core muscle mass has been used as a surrogate marker of sarcopenia and indicator of frailty. This study aimed to assess association between core muscle mass with sarcopenia screening tool SARC-F and Clinical Frailty Scale (CFS) in patients with AA. METHODS: Prospective audit of patients in pre-operative aortic clinic between 01/07/2019-31/01/2020 including frailty assessment using Rockwood CFS and sarcopenia screening using SARC-F questionnaire. Psoas and sartorius muscle area were measured on pre-operative CT scans and adjusted for height. Association was assessed using Spearman's rank correlation coefficient. RESULTS: Of 84 patients assessed, median age was 75 years [72,82], 84.5% were men, 65.5% were multimorbid and 63.1% had polypharmacy. Nineteen percent were identified as frail (CFS score >3) and 6.1% positively screened for sarcopenia (SARC-F score 4 or more). Median psoas area (PMA) at L3 was 5.6cm2/m2 [4.8,6.6] and L4 was 7.4cm2/m2 [6.3,8.6]. Median sartorius area (SMA) was 1.8 cm2/m2 [1.5,2.2]. CFS demonstrated weak but statistically significant negative correlation with height-adjusted PMA at L3 (r=-0.25, p=0.034) but not at L4 (r=-0.23, p=0.051) or with SMA (r=-0.22, p=0.065). No association was observed between SARC-F score and PMA or SMA (L3 PMA r=-0.015, p=0.9; L4 PMA r=-0.0014, p= 0.99; SMA r=-0.051, p=0.67). CONCLUSION: CFS showed higher association with CT-derived muscle mass than SARC-F. Comprehensive pre-operative risk-stratification tools which incorporate frailty assessment and body composition analysis may assist in decision making for surgery and allow opportunity for pre-habilitation.

Impact of methodological choices in comparative effectiveness studies: application in natalizumab versus fingolimod comparison among patients with multiple sclerosis.

BACKGROUND: Natalizumab and fingolimod are used as high-efficacy treatments in relapsing-remitting multiple sclerosis. Several observational studies comparing these two drugs have shown variable results, using different methods to control treatment indication bias and manage censoring. The objective of this empirical study was to elucidate the impact of methods of causal inference on the results of comparative effectiveness studies. METHODS: Data from three observational multiple sclerosis registries (MSBase, the Danish MS Registry and French OFSEP registry) were combined. Four clinical outcomes were studied. Propensity scores were used to match or weigh the compared groups, allowing for estimating average treatment effect for treated or average treatment effect for the entire population. Analyses were conducted both in intention-to-treat and per-protocol frameworks. The impact of the positivity assumption was also assessed. RESULTS: Overall, 5,148 relapsing-remitting multiple sclerosis patients were included. In this well-powered sample, the 95% confidence intervals of the estimates overlapped widely. Propensity scores weighting and propensity scores matching procedures led to consistent results. Some differences were observed between average treatment effect for the entire population and average treatment effect for treated estimates. Intention-to-treat analyses were more conservative than per-protocol analyses. The most pronounced irregularities in outcomes and propensity scores were introduced by violation of the positivity assumption. CONCLUSIONS: This applied study elucidates the influence of methodological decisions on the results of comparative effectiveness studies of treatments for multiple sclerosis. According to our results, there are no material differences between conclusions obtained with propensity scores matching or propensity scores weighting given that a study is sufficiently powered, models are correctly specified and positivity assumption is fulfilled.

Depicting the phenotypic space of the annual plant Diplotaxis acris in hyperarid deserts.

The phenotypic space encompasses the assemblage of trait combinations yielding well-suited integrated phenotypes. At the population level, understanding the phenotypic space structure requires the quantification of among- and within-population variations in traits and the correlation pattern among them. Here, we studied the phenotypic space of the annual plant Diplotaxis acris occurring in hyperarid deserts. Given the advance of warming and aridity in vast regions occupied by drylands, D. acris can indicate the successful evolutionary trajectory that many other annual plant species may follow in expanding drylands. To this end, we conducted a greenhouse experiment with 176 D. acris individuals from five Saudi populations to quantify the genetic component of variation in architectural and life history traits. We found low among-population divergence but high among-individual variation in all traits. In addition, all traits showed a high degree of genetic determination in our study experimental conditions. We did not find significant effects of recruitment and fecundity on fitness. Finally, all architectural traits exhibited a strong correlation pattern among them, whereas for life history traits, only higher seed germination implied earlier flowering. Seed weight appeared to be an important trait in D. acris as individuals with heavier seeds tended to advance flowering and have a more vigorous branching pattern, which led to higher fecundity. Population divergence in D. acris might be constrained by the severity of the hyperarid environment, but populations maintain high among-individual genetic variation in all traits. Furthermore, D. acris showed phenotypic integration for architectural traits and, to a lesser extent, for life history traits. Overall, we hypothesize that D. acris may be fine-tuned to its demanding extreme environments. Evolutionary speaking, annual plants facing increasing warming, aridity, and environmental seasonality might modify their phenotypic spaces toward new phenotypic configurations strongly dominated by correlated architectural traits enhancing fecundity and seed-related traits advancing flowering time.

Facilitation Effects of Haloxylon salicornicum Shrubs on Associated Understory Annuals, and a Modified "Stress-Gradient" Hypothesis for Droughty Times.

Perennial shrub-annual plant interactions play key roles in desert regions influencing the structure and dynamics of plant communities there. In the present study, carried out in northwestern Saudi Arabia, we examined the effect of Haloxylon salicornicum shrubs on their associated understory annual species across four consecutive growing seasons, along with a record of the seasonal rainfall patterns. We measured density and species richness of all the annual species in permanent quadrats located beneath individual shrubs, as well as in the spaces between shrubs. During wet growing season H. salicornicum shrubs significantly enhanced the density and species richness of sub-canopy species, whereas in the relatively dry seasons they exerted negative effects on the associated species. In all growing seasons, the presence of shrubs was associated with enhanced soil properties, including increased organic carbon content, silt + clay, and levels of nutrients (N, P and K). Shrubs improved soil moisture content beneath their canopies in the wet growing season, while in the dry seasons they had negative effects on water availability. Differences in effects of H. salicornicum on understory plants between growing seasons seem due to the temporal changes in the impact of shrubs on water availability. Our results suggest the facilitative effects of shrubs on sub-canopy annuals in arid ecosystems may switch to negative effects with increasing drought stress. We discuss the study in light of recent refinements of the well-known "stress-gradient hypothesis".

Potential of rice straw biochar, sulfur and ryegrass (Lolium perenne L.) in remediating soil contaminated with nickel through irrigation with untreated wastewater.

BACKGROUND: Untreated wastewater carries substantial amount of heavy metals and causes potential ecological risks to the environment, food quality, soil health and sustainable agriculture. METHODOLOGY: In order to reduce the incidence of nickel (Ni2+) contamination in soils, two separate experiments (incubation and greenhouse) were conducted to investigate the potentials of rice straw biochar and elemental sulfur in remediating Ni2+ polluted soil due to the irrigation with wastewater. Five incubation periods (1, 7, 14, 28 and 56 days), three biochar doses (0, 10 and 20 g kg-1 of soil) and two doses of sulfur (0 and 5 g kg-1 of soil) were used in the incubation experiment then the Ni2+ was extracted from the soil and analyzed, while ryegrass seeds Lolium perenne L. (Poales: Poaceae) and the same doses of biochar and sulfur were used in the greenhouse experiment then the plants Ni2+-uptake was determined. RESULTS: The results of the incubation experiment revealed a dose-dependent reduction of DTPA-extractable Ni2+ in soils treated with biochar. Increasing the biochar dose from 0 g kg-1 (control) to 10 or 20 g kg-1 (treatments) decreased the DTPA-extractable Ni2+ from the soil by 24.6% and 39.4%, respectively. The application of sulfur increased the Ni2+-uptake by ryegrass plant which was used as hyper-accumulator of heavy metals in the green house experiment. However, the biochar decreased the Ni2+-uptake by the plant therefore it can be used as animal feed. CONCLUSIONS: These results indicate that the biochar and sulfur could be applied separately to remediate the Ni2+-contaminated soils either through adsorbing the Ni2+ by biochar or increasing the Ni2+ availability by sulfur to be easily uptaken by the hyper-accumulator plant, and hence promote a sustainable agriculture.

Post-treatment endodontic pain following occlusal reduction in mandibular posterior teeth with symptomatic irreversible pulpitis and sensitivity to percussion: a single-centre randomized controlled trial.

AIM: This randomized, prospective, controlled trial assessed the effect of occlusal reduction on post-treatment endodontic pain and medication intake following root canal treatment of mandibular posterior teeth with symptomatic irreversible pulpitis with sensitivity to percussion treated in two visits. METHODOLOGY: Three hundred and eight patients were randomly assigned into two equal groups according to whether occlusal reduction was done or not (n = 154). For all patients, root canal treatment was carried out in two visits without intracanal medication. Patients assessed their pain using the 0-10 numerical rating scale (NRS) 6, 12, 24 and 48 h after the first visit (post-instrumentation) and 6 and 12 h following root canal filling (post-obturation). Patients, also, recorded their medication intake (sham or analgesic), post-instrumentation and post-obturation; patients initially received a sham capsule, but, if pain persisted, an analgesic was prescribed. Data were analysed using Mann-Whitney U-test, Friedman's test, Wilcoxon's rank test and chi-square (χ2 ) test. The relative risk (RR) and its 95% confidence interval (CI) were calculated for binary data. RESULTS: Occlusal reduction was associated with lower pain intensity than no occlusal reduction at 12 and 24 h post-instrumentation (P < 0.05). Pain intensity significantly and gradually decreased with both groups at all post-instrumentation and post-obturation time-points compared to preoperative pain (P < 0.05). The RR of moderate-to-severe pain was 0.61 (95% CI: 0.41, 0.91) 12 h post-instrumentation, and the RR of pain incidence, regardless of its level, was 0.75 (95% CI: 0.61, 0.92) 24 h post-instrumentation. There was no significant difference in medication intake (sham or analgesic) between groups (P > 0.05). CONCLUSIONS: Occlusal reduction was effective in reducing the intensity of postoperative pain 12 h and 24 h after root canal instrumentation in the first visit in patients with symptomatic irreversible pulpitis with sensitivity to percussion. Occlusal reduction lowered the risk of moderate-to-severe pain by about 40% 12 h post-instrumentation and the overall risk of pain by 25% 24 h post-instrumentation; yet, it did not affect medication intake.

Evaluation of postoperative pain intensity following occlusal reduction in teeth associated with symptomatic irreversible pulpitis and symptomatic apical periodontitis: a randomized clinical study.

AIM: To assess the effect of occlusal reduction on postoperative pain following two visits root canal treatment in posterior mandibular teeth with symptomatic irreversible pulpitis and symptomatic apical periodontitis in a randomized clinical trial. METHODOLOGY: This trial was conducted in the outpatient clinic of the Endodontic Department of the Faculty of Oral and Dental Medicine, Cairo University in Egypt. Forty-four-patients diagnosed with symptomatic irreversible pulpitis and symptomatic apical periodontitis were randomly assigned into two equal groups. The occlusal surfaces of teeth in the intervention group were reduced; whilst those assigned to the control group were left intact. Canal instrumentation was completed in the first visit using Revo-S rotary nickel-titanium files, and pain intensity was assessed using a visual analogue scale (VAS) at 6, 12, 24 and 48 h. Canal filling was completed 7 days later, and pain intensity was assessed at 6 and 12 h. A placebo was given and analgesics were prescribed to be administered in case of severe postoperative pain. Data were analysed using Independent t-test, chi-square and Fisher Exact tests. RESULTS: The mean pain scores within the two groups were associated with a significant continuous decrease over time. Following both instrumentation and canal filling, the mean pain scores in the intervention group were lower than those in the control group at all follow-up periods and this difference was only significant at 12 h (P = 0.021 and P = 0.015, respectively). CONCLUSIONS: Occlusal reduction reduced levels of postoperative pain in posterior mandibular teeth with symptomatic pulpitis and apical periodontitis only 12 h following both canal preparation and root filling.

3D FEA of cemented glass fiber and cast posts with various dental cements in a maxillary central incisor.

This study aimed to analyse and compare the stability of two dental posts cemented with four different luting agents by examining their shear stress transfer through the FEM. Eight three-dimensional finite element models of a maxillary central incisor restored with glass fiber and Ni-Cr alloy cast dental posts. Each dental post was luted with zinc phosphate, Panavia resin, super bond C&B resin and glass ionomer materials. Finite element models were constructed and oblique loading of 100 N was applied. The distribution of shear stress was investigated at posts and cement/dentine interfaces using ABAQUS/CAE software. The peak shear stress for glass fiber post models minimized approximately three to four times of those for Ni-Cr alloy cast post models. There was negligible difference in peak of shear stress when various cements were compared, irrespective of post materials. The shear stress had same trend for all cement materials. This study found that the glass fiber dental post reduced the shear stress concentration at interfacial of post and cement/dentine compared to Ni-Cr alloy cast dental post.

Toxicity of naturally occurring Bio-fly and chitosan compounds to control the Mediterranean fruit fly Ceratitis capitata (Wiedemann).

The efficacy of five compounds of a biopolymer chitosan and Bio-fly (Beauveria bassiana fungus) as biopesticide was evaluated on Ceratitis capitata under laboratory conditions. The inhibitory effects on acetylcholinesterase (AChE) and adenosinetriphosphatase (ATPase) as biochemical indicators were also determined in vivo. The results indicated that B. bassiana based Bio-fly exhibited significant toxicity against C. capitata (LC50 = 3008 and 3126 mg/L after 48 h in females and males, respectively) followed by the derivatives of chitosan, N-(4-propylbenzyl)chitosan and N-(2-nitrobenzyl)chitosan. Bio-fly displayed remarkable inhibition of AChE activity (IC50 = 2220 mg/L) while N-(2-chloro,6-flourobenzyl)chitosan, N-(4-propylbenzyl)chitosan and N-(3,4-methylenedioxybenzyl) chitosan had no significant difference in inhibitory action. In adult males, N-(2-nitrobenzyl)chitosan exhibited the highest inhibitory action (IC50 = 6569 mg/L). In addition, the toxic effects of the tested compounds on the activity of ATPase indicated that highly significant inhibition was found with N-(4-propylbenzyl)chitosan with an IC50 of 8194 and 8035 mg/L, in females and males, respectively.

Basic fibroblast growth factor and tumour necrosis factor alpha in vitiligo and other hypopigmented disorders: suggestive possible therapeutic targets.

BACKGROUND: In healthy skin, there is a molecular microenvironment that favours the survival of melanocytes and regulates their function. Keratinocytes synthesize and secrete several cytokines that have stimulatory and inhibitory effects on melanocytes. AIM OF THE WORK: This work was conducted to evaluate the expression of basic fibroblast growth factor (bFGF) and tumour necrosis factor alpha (TNF-α) mRNA levels in lesional skin of vitiligo, hypopigmented mycosis fungoides and hypopigmented tinea versicolor. PATIENTS AND METHODS: Forty eight patients (25 vitiligo, 14 hypopigmented mycosis fungoides, 9 hypopigmented tinea versicolor) and 10 healthy controls were included. A 4 mm punch skin biopsy was taken from lesional skin of patients, and the normal skin of controls for quantitative PCR examination of TNF-α and bFGF mRNA. RESULTS: The level of TNF-α mRNA in lesional skin of the three studied disorders was significantly higher than in the control group, while the level of bFGF mRNA was significantly lower in lesional skin of the three diseases than the control skin. A significant inverse correlation was demonstrated between the mRNA levels of the two studied cytokines in vitiligo and hypopigmented MF lesions. CONCLUSION: The study's findings demonstrate that the studied hypopigmented (vitiligo, hypopigmented MF, hypopigmented TV) disorders show similar changes in their cutaneous microenvironment with increased TNF-α and decreased bFGF mRNA expression. This cytokine microenvironment change may be implicated in the pigment loss and hence these cytokines may have future therapeutic implications.

Among- and within-population variation in flowering time of Iberian Arabidopsis thaliana estimated in field and glasshouse conditions.

The study of the evolutionary and population genetics of quantitative traits requires the assessment of within- and among-population patterns of variation. We carried out experiments including eight Iberian Arabidopsis thaliana populations (10 individuals per population) in glasshouse and field conditions. We quantified among- and within-population variation for flowering time and for several field life-history traits. Individuals were genotyped with microsatellites, single nucleotide polymorphisms and four well-known flowering genes (FRI, FLC, CRY2 and PHYC). Phenotypic and genotypic data were used to conduct Q(ST)-F(ST) comparisons. Life-history traits varied significantly among- and within-populations. Flowering time also showed substantial within- and among-population variation as well as significant genotype × environment interactions among the various conditions. Individuals bearing FRI truncations exhibited reduced recruitment in field conditions and differential flowering time behavior across experimental conditions, suggesting that FRI contributes to the observed significant genotype × environment interactions. Flowering time estimated in field conditions was the only trait showing significantly higher quantitative genetic differentiation than neutral genetic differentiation values. Overall, our results show that these A. thaliana populations are genetically more differentiated for flowering time than for neutral markers, suggesting that flowering time is likely to be under divergent selection.

Tc-99m diethylenetriamine pentaacetic acid (DTPA) renal function reserve estimation: is it a reliable predictive tool for assessment of preclinical renal involvement in scleroderma patients?

Prognosis of systemic sclerosis (SSc) depends on internal organ involvement. We assessed the value of renal function reserve (RFR) for the detection of preclinical nephropathy in scleroderma. Thirty SSc patients with normal serum creatinine and 30 healthy controls were included. Medsger disease severity score, glomerular filtration rate (GFR), and microalbuminuria were measured. Tc-99m DTPA was utilized for GFR measurement at baseline and after oral protein overload (stimulated GFR). RFR was calculated as the percentile increase of stimulated GFR. SSc patients had lower means of baseline GFR (P=0.001), stimulated GFR (P=0.004), RFR (P=0.046), and higher microalbuminuria (P=0.009) than controls. According to baseline GFR, SSc patients showed three categories-normal baseline GFR (n=12), hyperfiltration GFR (n=3), and reduced baseline GFR (n=15). In the former category, RFR was normal in 6/12 patients and abnormal in the remainders (50%). Hyperfiltration patients and those with reduced baseline GFR showed abnormal RFR. A statistically significant negative association was found between microalbuminuria versus stimulated GFR and RFR (r= -0.5, P=0.007 and r= -0.45, P=0.013, respectively). The majority of SSc patients with abnormal RFR had disease duration of ≥48 months (60% vs. 20%, P=0.008). All SSc patients with pulmonary hypertension had abnormal RFR, while reduced baseline GFR was noted in only 60%. A significant negative correlation was found between reduced baseline GFR and cumulative dose of corticosteroids in SSc patients (r= -0.4, P=0.022). RFR estimation could be a useful predictive marker for preclinical renal involvement in SSc patients so that early prophylactic measures and therapy modifications could be considered.

Soil seed bank in different habitats of the Eastern Desert of Egypt.

The floristic composition and species diversity of the germinable soil seed bank were studied in three different habitats (desert salinized land, desert wadi, and reclaimed land) in the Eastern Desert of Egypt. Moreover, the degree of similarity between the seed bank and the above-ground vegetation was determined. The seed bank was studied in 40 stands representing the three habitats. Ten soil samples (each 25 × 20 cm and 5 cm depth) were randomly taken per stand. The seed bank was investigated by the seedling emergence method. Some 61 species belonging to 21 families and 54 genera were identified in the germinable seed bank. The recorded species include 43 annuals and 18 perennials. Ordination of stands by Detrended Correspondence Analysis (DCA) indicates that the stands of the three habitats are markedly distinguishable and show a clear pattern of segregation on the ordination planes. This indicates variations in the species composition among habitats. The results also demonstrate significant associations between the floristic composition of the seed bank and edaphic factors such as CaCO3, electrical conductivity, organic carbon and soil texture. The reclaimed land has the highest values of species richness, Shannon-index of diversity and the density of the germinable seed bank followed by the habitats of desert wadi and desert salinized land. Motyka's similarity index between the seed bank and the above-ground vegetation is significantly higher in reclaimed land (75.1%) compared to desert wadi (38.4%) and desert salinized land (36.5%).

Composition and diversity of weed communities in Al-Jouf province, northern Saudi Arabia.

The aim of this study was to identify the main weed communities in Al-Jouf province in northern Saudi Arabia. Moreover, the composition and diversity of these communities were studied in relation to soil variables and crop type. Some 54 stands representing olive orchards, date palm orchards, wheat crop and watermelon crop were studied, using ten quadrats (1 × 1 m) per stand. A total of 71 species belonging to 22 families and 61 genera were observed. The classification of vegetation using the Two Way Indicator Species Analysis (TWINSPAN) resulted in the recognition of four vegetation groups representing wheat crop, orchards in winter season, orchards in summer season and watermelon crop. These results suggested the importance of both crop and season for the formation of weed community. Detrended Correspondence Analysis (DCA) showed that these groups are clearly distinguished by the first two DCA axes. The species richness was higher in both olive and date palm orchards than in wheat and watermelon crops. This pattern of species richness could be related to farm management practices and habitat micro-heterogeneity. Soil electrical conductivity, organic carbon and soil texture showed significant correlations with species richness and the cover values of some dominant species, suggesting the significant role of soil characteristics in weed community structure and diversity.

Temporal variation in genetic diversity and effective population size of Mediterranean and subalpine Arabidopsis thaliana populations.

Currently, there exists a limited knowledge on the extent of temporal variation in population genetic parameters of natural populations. Here, we study the extent of temporal variation in population genetics by genotyping 151 genome-wide SNP markers polymorphic in 466 individuals collected from nine populations of the annual plant Arabidopsis thaliana during 4 years. Populations are located along an altitudinal climatic gradient from Mediterranean to subalpine environments in NE Spain, which has been shown to influence key demographic attributes and life cycle adaptations. Genetically, A. thaliana populations were more variable across space than over time. Common multilocus genotypes were detected several years in the same population, whereas low-frequency multilocus genotypes appeared only 1 year. High-elevation populations were genetically poorer and more variable over time than low-elevation populations, which might be caused by a higher overall demographic instability at higher altitudes. Estimated effective population sizes were low but also showed a significant decreasing trend with increasing altitude, suggesting a deeper impact of genetic drift at high-elevation populations. In comparison with single-year samplings, repeated genotyping over time captured substantially higher amount of genetic variation contained in A. thaliana populations. Furthermore, repeated genotyping of populations provided novel information on the genetic properties of A. thaliana populations and allowed hypothesizing on their underlying mechanisms. Therefore, including temporal genotyping programmes into traditional population genetic studies can significantly increase our understanding of the dynamics of natural populations.