Hydraulic Retention Time Influence on Improving Flocculation in the Activated Sludge Processes Through Polyelectrolytes

Hydraulic retention time (HRT) influence improving sludge flocculation with adding the polyelectrolytes (non-ionic, anionic, and cationic) was studied on an activated sludge (AS) system fed with synthetic domestic wastewater (SDW), dairy industry wastewater (DIW), and caramel industry wastewater (CIW). The sludge volumetric index, food/microorganism ratio (F/M), and mixed liquor volatile suspended solids at different HRTs (6, 8 and 10 h) were monitored on an experimental model. Results showed that both SDW and IW had the best sludge flocculation conditions at 8 h and 100 mL of non-ionic polyelectrolyte (0.2 mg L^?1). In addition, this phenomenon reached the organic matter removal efficiencies of 95.9, 95.7, and 94.2% for SDW, DIW, and CIW, respectively. Therefore, optimum HRT increased the organic matter removal efficiencies by 10%, sludge concentration by 37% (22–55%), and F/M ratio by 70%. Moreover, the polyelectrolytes used in AS improved the sludge flocculation by 2.9 times.     

Comparison of larval thermal maxima between <Emphasis Type="Italic">Fundulus heteroclitus</Emphasis> and <Emphasis Type="Italic">F. grandis</Emphasis>

Fundulus heteroclitus and F. grandis are resident salt marsh fishes that overlap in distribution over a narrow range in northeastern Florida. The objective of the present study was to examine whether the limits of the species’ ranges could be explained by differences in thermal tolerance. Two populations of each species were collected and then spawned in the laboratory, and 9-day-old larvae were used for critical thermal maxima trials. Mean LOE temperatures of larvae ranged from 43.04 to 43.65°C and showed little difference between species. Therefore, differences in high temperatures experienced cannot account for the differences of the distributions of the two species. Condition-specific competition may play a greater role in determining the observed range of the two species.     

The reproductive biology of okra. 2. Self-fertilization kinetics in the cultivated okra (Abelmoschus esculentus), and consequences for breeding

Summary The use of Cruden's index (1977), for studying okra sexual reproductive allocations, indicates a facultative autogamy mode. The purpose of the research described is to obtain more accurate information on the self-fertilization process. For this, self-pollen grain germination was stopped at different times of the day. Twelve varieties of Abelmoschus esculentus were used. Self-fertilization kinetics—expressed by the setting rate—displayed an increase between 7.00 to 16.00 hr. Study of obtained progenies, by stimulated allogamy, confirmed the process and showed that allo-pollen grains deposited on a stigma after midday had only a very little chance of contributing to fertilization. As a result, the polymorphism of the flower structure and particularly the distance between anther and stigmas, insect types and movement habits play major roles in governing okra allogamy. We also show that self-fertilization kinetics can be used to improve controlled hybrid production.     

Analysis of rice blast resistance gene <Emphasis Type="Italic">Pi</Emphasis>-<Emphasis Type="Italic">z</Emphasis> in rice germplasm using pathogenicity assays and DNA markers

The Pi-z gene in rice confers resistance to a wide range of races of the rice blast fungus, Magnaporthe oryzae. The objective of this study was to characterize Pi-z in 111 rice germplasm accessions using DNA markers and pathogenicity assays. The existence of Pi-z in rice germplasm was detected by using four simple sequence repeat (SSR) markers (RM527, AP4791, AP5659-1, AP5659-5) closely linked to Pi-z, and was verified using pathogenicity assays with an avirulent strain (IE1k) and two virulent races (IB33 and IB49). Among 111 germplasm accessions evaluated, 73 were found to contain the Pi-z gene using both SSR markers and pathogenicity assays. The remaining 38 germplasm accessions were found to be inconsistent in their responses to the blast races IB33, IEIk and IB49 with expected SSR marker alleles, suggesting the presence of unexpected SSR alleles and additional R gene(s). These characterized germplasm can be used for genetic studies and marker-assisted breeding for improving blast resistance in rice.     

Assessing the Impacts of Time-to-Detection Distribution Assumptions on Detection Probability Estimation

Abundance estimates from animal point-count surveys require accurate estimates of detection probabilities. The standard model for estimating detection from removal-sampled point-count surveys assumes that organisms at a survey site are detected at a constant rate; however, this assumption can often lead to biased estimates. We consider a class of N-mixture models that allows for detection heterogeneity over time through a flexibly defined time-to-detection distribution (TTDD) and allows for fixed and random effects for both abundance and detection. Our model is thus a combination of survival time-to-event analysis with unknown-N, unknown-p abundance estimation. We specifically explore two-parameter families of TTDDs, e.g., gamma, that can additionally include a mixture component to model increased probability of detection in the initial observation period. Based on simulation analyses, we find that modeling a TTDD by using a two-parameter family is necessary when data have a chance of arising from a distribution of this nature. In addition, models with a mixture component can outperform non-mixture models even when the truth is non-mixture. Finally, we analyze an Ovenbird data set from the Chippewa National Forest using mixed effect models for both abundance and detection. We demonstrate that the effects of explanatory variables on abundance and detection are consistent across mixture TTDDs but that flexible TTDDs result in lower estimated probabilities of detection and therefore higher estimates of abundance.Supplementary materials accompanying this paper appear on-line.     

Rejuvenating indigenous trees in agroforestry parkland systems for better fruit production using crown pruning

The effects of crown pruning of mature indigenous fruit trees of Vitellaria paradoxa C. F Gaertn (commonly known as karité) and Parkia biglobosa (Jacq.) R. Br. ex G. Don (commonly known as néré) on recovery of crown size and fruit yield were assessed during 6 years in an agroforestry parkland system in Burkina Faso. Three treatments of crown pruning (total-pruning, half-pruning and a control of no-pruning) were applied to karité and néré. Each treatment comprised ten individuals of each species or a total of 60 trees of both species. Six years after pruning, higher recovery (81%) of crown diameter was achieved in total-pruned trees of néré as opposed to karité which recovered by only 73%. On the contrary, fruit production in total-pruned trees of karité recovered by 83% 5 years after pruning and fully (100%) 6 years after pruning as opposed to néré which recovered by only 57% 5 years after pruning but declined to 16% on the sixth year probably due to interannual variability. Fruit yields did not differ significantly between unpruned and half-pruned trees of both species throughout the experiment period. Total pruning may, therefore, be recommended to farmers to rejuvenate old trees of karité in parklands on the basis of fast recovery of fruit and slow recovery of crown in the species. Slow recovery of crown in pruned trees is the most desirable characteristic in parklands in order to avoid the negative effect of tree shade on adjacent crop.     

Limited awareness of animal influenza prevention and control among Dai Lue smallholder farmers in Southwest China

Awareness of animal influenza and its prevention and control is important for ensuring livestock health, production and welfare. In China, a country stereotyped as a major source of emerging zoonotic infectious diseases, research on the public understanding of animal influenza is limited to the Han, the main ethnic group. The present qualitative study in Southwest China investigated awareness of animal influenza among the Dai, an ethnic minority. The participants (15 men and 10 women, ages 18–83) were smallholder farmers of pigs and poultry in rural areas of Jinghong, Xishuangbanna, Yunnan Province. A mixture of interviews and group discussions took place in homes and villages. The participants were asked about their knowledge of avian influenza (H7N9), swine influenza (H1N1), precautions taken to protect against influenza, procedures when animals were sick and perceived risk of animal influenza. The data were analysed following coding and thematic analysis. The findings demonstrated a limited understanding of animal health and welfare among participants. Specifically, they were largely unaware of animal influenza (H7N9, H1N1) including its causes, symptoms, prevention and treatment. The farmers were also uninformed of the risks they faced and unknowingly engaged in behaviours which increased direct or indirect exposure to infected animals, a risk factor for human infection. They also reported poor usage of veterinary services. In order to guarantee the health, welfare and production of their livestock, immediate action is needed to enable Dai smallholder farmers to prevent and respond to animal influenza effectively and timely.     

Retrospective evaluation of sildenafil citrate as a therapy for pulmonary hypertension in dogs

Pulmonary arterial hypertension (PH) is a pathologic condition in dogs characterized by abnormally high pressures in the pulmonary circulation and has been associated with a poor outcome. Sildenafil is a type V phosphodiesterase inhibitor that produces nitric oxide mediated vasodilatation. Sildenafil treatment decreases pulmonary arterial pressure and pulmonary vascular resistance in people with PH. The purpose of this study was to describe the clinical characteristics and outcome of dogs with PH treated with sildenafil. The cardiology database was searched for dogs with PH treated with sildenafil. PH was defined as systolic pulmonary arterial pressure (PAPs) > or = 25 mmHg at rest. Medical records were reviewed for the following information: signalment, duration and type of clinical signs before treatment, underlying disease, estimated or measured PAPs, dosage and dosing interval of sildenafil, and the effect of treatment on clinical signs and pulmonary arterial pressure and survival time. Thirteen affected dogs were identified. Clinical signs included collapse, syncope, respiratory distress, and cough. Duration of clinical signs before presentation ranged from 3 days to 5 months. An underlying cause was identified in 8 dogs. The median sildenafil dosage was 1.9 mg/kg. Ten dogs received concurrent medications. Median PAPs was 90 mmHg; 8 dogs were reevaluated after therapy, and the median decrease in PAPs was 16.5 mmHg. The median survival time of all dogs was 91 days. Sildenafil appeared to be well tolerated in dogs with PH and was associated with decreased PAPs and amelioration of clinical signs in most. Sildenafil represents a reasonable treatment option for dogs with pulmonary hypertension.     

Diagnosis and successful treatment of Cryptococcus neoformans variety grubii in a domestic ferret

A domestic ferret was presented for episodic regurgitation. Cytologic examination and culture of an enlarged submandibular lymph node revealed Cryptococcus neoformans variety grubii (serotype A). The ferret was successfully treated with itraconazole. This is the first documented case of Cryptococcus neoformans variety grubii in a ferret in the United States.