Surface Feeder Research Articles

Heavy Metal Concentrations in Water, Sediment, and Fish Species in Chashma Barrage, Indus River: A Comprehensive Health Risk Assessment.

The increasing levels of heavy metals in aquatic environments, driven by human activities, pose a critical threat to ecosystems' overall health and sustainability. This study investigates the bioaccumulation of heavy metals (Pb, Cu, Cr, and Cd) in water, sediment, and three fish species (Catla catla, Labeo rohita, Cirrhinus mrigala) of different feeding zones within Chashma Barrage, located in the Mianwali district of Punjab, Pakistan, on the Indus River. A comprehensive analysis, including an assessment of associated human health risks, was conducted. Thirty samples from all three sites for each fish species, with an average body weight of 160 ± 32g, were collected from Chashma Barrage. Water quality parameters indicated suitability for fish growth and health. Heavy metal concentrations were determined using an atomic absorption spectrometer. Results indicated elevated levels of Cd, Cr, and Cu in sediment and Pb and Cd in water, surpassing WHO standard limits. Among the fish species, bottom feeder (C. mrigala) exhibited significantly (P < 0.05) higher heavy metal levels in its tissues (gills, liver, and muscle) compared to column feeder (L. rohita) and surface feeder (C. catla). Liver tissues across all species showed higher heavy metal bioaccumulation, followed by gills. Principal component analysis (PCA) revealed strong correlations among heavy metals in sediment, gills, muscle, and water in every fish species. However, the vector direction suggests that Cr was not correlated with other heavy metals in the system, indicating a different source. The human health risk analysis revealed lower EDI, THQ, and HI values (< 1) for the fish species, indicating no adverse health effects for the exposed population. The study emphasizes the bioaccumulation differences among fish species, underscoring the higher heavy metal concentrations in bottom feeder fish within Chashma Barrage.

Implications of Heavy Metal Accumulation in Fish Feed, Water, Sediment, and Different Fish Species in a Polyculture System.

Heavy metal bioaccumulation in organisms is primarily a result of dietary uptake. The current study examines the concentrations of heavy metals (Pb, Cd, Cr, and Cu) in fish feed, water, sediment, and three fish species (Catla catla, Labeo rohita, and Cyprinus carpio) from different feeding zones in a polyculture pond system. Furthermore, associated human health risks were also evaluated. The fish samples (n = 25 for each species) were collected from 10 different fish ponds in the Kohat district, Pakistan. Heavy metals were determined using an atomic absorption spectrometer. Results revealed higher concentrations of heavy metals in sediment, followed by water. However, the concentration of heavy metals in fish feed was lower than the standard limits. In the case of fish, the bottom feeder (C. carpio) notably exhibited higher (P < 0.05) levels of heavy metals than the column feeder (L. rohita) and surface feeder (C. catla) fish. Moreover, in the liver of all fish species, the bioaccumulation of heavy metals was higher, followed by the gills. Principal component analysis (PCA) demonstrated a strong correlation of heavy metals in C. carpio gills, flesh, feed, and pond water, while the heavy metals in the liver correlated with the detected metals in sediment. The human health risk analysis shows that bottom feeder fish had higher estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) values (> 1). Consequently, the exposed population may experience adverse health effects. The findings of this study suggest that the bottom feeder (C. carpio) bioaccumulates a higher concentration of heavy metals than column (L. rohita) and surface feeder (C. catla) in the polyculture system.

Bioaccumulation of polystyrene microplastics and changes in antioxidant and AChE pattern in a freshwater snail (Filopaludina bengalensis) from river Ganga

Microplastic pollution is a leading global problem affecting terrestrial and marine aquatic ecosystems. Due to the stagnant nature of microplastics, the toxic effect of microplastics is more pronounced to benthic organisms than the surface feeder. Hence, the present study effort was to study the microplastic bioaccumulation pattern and changes in the enzymatic and nonenzymatic antioxidant and AChE pattern of freshwater snail Filopaludina bengalensis, which were subjected to 0.5 ppm to 5 ppm levels of polystyrene microsphere (∼ 30 µm) for 27 days. The study showed that microplastics were easily accumulated in the test organism in a dose and time-dependent manner, amounting to 82 ± 6.02 particles /individuals at a 5 ppm dose on the 27th day. However, no mortality was observed at the test microplastic dosages. The enzymatic antioxidant profile (SOD and catalase) showed limited variability and remained stable with increased duration and microplastic dose. However, the nonenzymatic antioxidant profile showed distinct variability with the complete seizing of the DPPH activity on the 27th day at 5 ppm microplastic dose and a gradual decrease of ABTS and FRAP activity at all the dose ranges. Even the AChE activity decreased with higher exposure concentrations. The present study for the first time shows the direct impact of microplastics on a freshwater snail widely available in the Indian subcontinent, indicating the role of microplastic pollution will create havoc in the Ganga river eco-biosystem in the long run.

KOMUNIKASI SINGKAT: KEBIASAAN MAKAN IKAN KEPALA TIMAH (Aplocheilus panchax, Hamilton 1822) DI PERAIRAN EKSTREM ASAM PASCATAMBANG TIMAH TERABAIKAN

Kepala Timah (Aplocheilus panchax, Hamilton 1822) is one of the fish that has the survival abilities to live in a wide variety of quality waters. The ability of A. panchax to survive in acidic waters has begun to be widely studied as extremophile fish to study ecosystems in aquatic habitats that have acidic characteristics. This study aimed to determine the food habits of A. panchax as natural food in acid water of abandoned ex-tin mining activity. The results showed that the natural food for A. panchax was insects larvae or insects that fall on the surface of the waters. The food habits and terminal mouth type confirmed that A. panchax was surface feeder fish, carnivorous fish, larvivorous or insectivorous fish. The sagittiform body type was used A. panchax to did the strategy of feeding behavior by pursue or ambush their prey and it indicated that A. panchax as ambush predator.

IMPACT OF HABITAT QUALITY VARIATIONS ON SOMEBEHAVIOURAL ASPECTS OF LARVIVOROUS FISH

Over 85 per cent of all known animal species belong to Arthropoda which includes the vectors of most important diseases. They affect our health either directly by bites, stings or indirectly throughdisease transmission. Several genera of Arthropods like mosquitoes, flies, ticks and mites play animportant role in human disease transmission. The most significant vector borne disease transmission is by blood feeding insects. Utilization of larvivorous fish in vector borne disease control programme is gaining momentum. Poecilia reticulata survives in all types of water bodies and can tolerate high degree of pollution. It is prolific breeder and surface feeder, carnivorous, thus efficient larvivorous fish. Present investigation reveals that low oxygen content in sewage water and surface feeding nature make it to stay at surface waters for longer time as compared to pond water.

First documentation of plastic ingestion in the arctic glaucous gull (Larus hyperboreus)

Arctic wildlife is facing multiple stressors, including increasing plastic pollution. Seabirds are intrinsic to marine ecosystems, but most seabird populations are declining. We lack knowledge on plastic ingestion in many arctic seabird species, and there is an urgent need for more information to enable risk assessment and monitoring. Our study aimed to investigate the occurrence of plastics in glaucous gulls (Larus hyperboreus) breeding on Svalbard. The glaucous gull is a sentinel species for the health of the arctic marine ecosystem, but there have been no studies investigating plastic occurrence in this species since 1994. As a surface feeder and generalist living in an area with high human activity on Svalbard, we expected to find plastic in its stomach. We investigated for plastic >1 mm and documented plastic ingestion for the first time in glaucous gulls, with a frequency of occurrence of 14.3% (n = 21). The plastics were all identified as user plastics and consisted of polypropylene (PP) and polystyrene (PS). Our study provides new quantitative and qualitative data on plastic burden and polymer type reported in a standardized manner establishing a reference point for future research and monitoring of arctic gulls on national and international levels.

Physical and mathematical modeling of the moving the raw cotton between directing wall and area ginning seeds

In article are brought algorithm and results brought numerically-experimental studies on qualitative and quantitative estimation of the law of the moving the raw cotton from directing walls outgoing between spiked-drum and netlike surface feeder aside worker of the camera ginning machines. It is known that the uniform supply of raw cotton to the ginning process has a direct impact on the efficiency of the ginning process. In the process of ginning, the cotton is cleaned on the surface of the pile drum and net of the supplier, and the crushed gin comes to the working chamber through the gin. As a result of the rotation of the saw cylinder in the working chamber, the cotton fiber is suspended and the rotation is started. As a result of the circular motion of the raw cotton, a raw material roller is formed. In this process, the actual problem is to ensure that the raw cotton consists of small pieces and is uniform in time and width of the equipment. The Comparison got given on calculation shows that increase the corner will bring about increase the growing forming displacement. Increase of this corner will bring the leaflet of the raw cotton about increase of length free moving.

Pattern of spatio-temporal fish diversity in association with habitat gradients in a tropical reservoir, India

Abstract Reservoirs are aquatic resources with the potential to increase India's fish production through inland fisheries. Thippagondanahalli is a medium-size reservoir on Arkavathy River, a tributary of the Cauvery. It is located in Bangalore rural district of Karnataka (12°58’24” to 12°96'49" N 77°20’33” to 77°35’63” E) and has a water surface area of 1162 ha at full reservoir level and 784.55 m at full supply level. Fish diversity studies were conducted to examine the spatial and temporal variations in fish diversity in relation to habitat parameters. A taxonomic abundance of 25 fish species (80% of them native) belonging to 14 families and 4 orders was recorded. A range of statistical estimators such as Chao 1, Jack 1, and Bootstrap were used to assess the expected species richness. The Jack 1 method showed the highest abundance with 28 species. The littoral zone, dominated by small indigenous species, was found to have relatively higher fish diversity (Shannon index-1.86) compared to the limnetic zone of the reservoir. Shannon diversity was higher in the monsoon season (1.76) compared to other seasons. Physico-chemical parameters revealed that this waterbody is highly eutrophic. Canonical correspondence analysis between seasonal habitat characteristics and seasonal species abundance showed the abundance of the small indigenous fish Amblypharyngodon mola during the post-monsoon season, the bottom feeder Cirrhinus mrigala and the surface feeder Rasbora daniconius during the monsoon season, and the carnivores Mystus malabaricus and Channa orientalis as well as the planktivore Puntius sarana during the pre-monsoon season. This study suggests the use of fisheries management and conservation measures such as fish-aggregating devices, stocking of certified seed, and impact assessment of exotic species.

Total organic carbon, heavy metal content and metal bioaccumulation in a freshwater wetland of Indo-Burmese province, India

ABSTRACT This study attempts to assess the spatio-temporal distribution of total organic carbon (TOC) and heavy metals in one of the Ramsar wetlands of Indo-Burmese province. Water samples were collected from 10 sampling points during the premonsoon, monsoon and postmonsoon season of 2016 and 2017. The general water parameters such as low DO, high BOD, and high fluoride imply the wetland water’s deteriorated quality. The mean TOC of water was estimated to be 2.4 ± 0.33 ppm, the first report from Deepor Beel. Pearson’s correlation coefficient showed a significant positive relation (> 0.7) between TOC, phosphate, and nitrate, which indicates the seasonal inflow of these parameters from a similar source. The computed heavy metal indices revealed that most of the water samples were highly contaminated by metals. The metal concentration recorded in the selected macrophytes and fishes species was far above the concentration of the respective metal in the water samples. Metal distribution in plant samples disclosed that Euryale ferox showed better accumulation ability than Hydrilla verticillata and Eichhornia crassipes. Among the fish species, the highest metal accumulation was recorded in Xenentodon cancila (zinc, iron, manganese, and nickel) and Channa punctatus (lead and cadmium). In the fish samples, metal accumulation was found to be higher in the organs (particularly in the kidney) than in the muscles. Bioconcentration factor revealed a high metal accumulation in the submerged type plants and surface feeder fishes.

Persistent organic pollutants (POPs) in fish species from different lakes of the lesser Himalayan region (LHR), Pakistan: The influence of proximal sources in distribution of POPs

Fish dwelling in remote mountain water systems are sensitive to long term exposure of POPs and can be used as an important bioindicator of POPs pollution in fragile mountain ecosystems. Current study aimed to investigate the concentrations and patterns of organic pollutants in fish tissues from different lakes of the Lesser Himalayan Region (LHR). OCPs, PCBs, PBDEs were analyzed in four common edible fish species of the LHR: Oncorhynchus mykiss, Labeo rohita, Hypophthalmichthys molitrix and Orechromis aureus. The fish were collected from lakes with different types of catchment areas (glacial, non-glacial mountain region and urban region) and extent of anthropogenic influence. The levels OCPs, PCBs and PBDEs analyzed in the selected fish species were in range of 0.21–587, 6.4–138 and 1.2–14 ng g−1 lw, respectively. The ∑DDTs, higher chlorinated PCBs, tetra- and penta-BDEs were more prevalent in urban and remote lakes whereas pp’-DDE, lower chlorinated PCBs and BDE-47 and -99 were predominant in fish species from glacial lakes. ∑DDTs, ∑PCBs and ∑PBDEs showed statistically significant differences (p < 0.05) among species, trophic guilds (carnivore, herbivore and omnivore) and feeding regimes (surface, bottom and column feeder) and ∑HCH showed a significant difference only among trophic guilds. The stable isotope values of δ 15N and δ13C differed significantly among species for ∑HCH, ∑PCBs, ∑PBDEs (p < 0.05) and ∑DDT (p < 0.01). The range of δ13C values (−34 to −19‰) indicated the importance of littoral and pelagic sources of dietary carbon. Trophic position and dietary proxies were identified as important variables for explaining the variability of the studied compounds. Kohonen self-organizing maps (SOM) showed that in addition to trophic position and other physiological characteristics of fish, that the type of lakes and proximal sources of POPs were the most important predictors for distribution of organic contaminants in fish samples from LHR.

Consumptive Use, Water Use Efficiency, Moisture Depletion Pattern of Wheat under Semi-arid Eastern Plain Zone of Rajasthan

Background: India has the largest area under wheat cultivation but variability in climate is one of the major environmental threat to agriculture particularly wheat crop. The growth and yield of wheat crop is adversely affected by environmental stresses such as soil moisture deficit, high temperature, low light intensity etc. Among these stresses irrigation water is a scare resource, it’s optimization is fundamental to water resources use. It permits better utilization of all other production factors and thus leads to increased yields per unit area and time. The higher requirement of food to feed the increased population with reduced water availability for crop production forces the irrigation researchers and managers to use water-saving irrigation strategies to improve the water productivity (WP) in recent years. Thus, an assessment of the potential for reducing water needs and increasing production is the need of time. The current study aimed to study of this province in order to manage and control related problems. Method: In this context a field experiment was conducted during Rabi season 2016 and 2017, Soil moisture studies were started right from sowing and continued up to maturity of wheat crop. The soil moisture content under all the treatments of three replications was determined just before irrigation and twenty four hours after irrigation from 0-15, 15-30, 30-45 and 45-60 cm soil depths and calculate consumptive use of water, soil moisture depletion pattern and water use efficiency. Result: Results revealed that the maximum consumptive use (350.01 mm) of water found with irrigation schedule at 1.2 ETc and highest water use efficiency (15.32 kg ha-1 mm-1) obtained with irrigation schedule at 1.0 ETc. Among the different wheat cultivars Raj-4120 registered higher consumptive use (332.57 mm) and Raj- 4238 obtained highest water use efficiency (16.13 kg ha-1 mm-1) while crop sown on 15th November recorded higher consumptive use (333.04 mm) and water use efficiency (15.69 kg ha-1 mm-1). Wheat is a surface feeder with fibrous root system, the maximum amount of moisture was depleted in shallow depth (0-15 cm) than deeper layers of soil.

Enzymatic, non enzymatic antioxidants and glucose metabolism enzymes response differently against metal stress in muscles of three fish species depending on different feeding niche

Current study aims to determine difference in metal accumulation pattern in muscle of Liza parsia (pelagic, omnivore), Amblypharyngodon mola (surface feeder, herbivore) and Mystus gulio (benthic, carnivore) depending on their niche and feeding habit and how it affects the endogenous antioxidants and glucose metabolism in fish muscle. Fishes were collected from Malancha, Diamond Harbour and Chandanpiri, West Bengal, India. Concentrations of lead, zinc, cadmium, chromium were measured in water, sediment and fish muscle. Metal pollution index (MPI) and bioconcentration factor (BCF) was calculated to evaluate the ability of fish to accumulate specific metals in muscle tissue from the aquatic environment. Metal concentrations were found significantly higher (P < 0.05) in water, sediment, fish muscles from Malancha than Chandanpiri and Diamond Harbour. L. parsia (MPI: 0.4–1.6) showed highest metal deposition in their muscle followed by A. mola (MPI: 0.37–1.38) and M. gulio (MPI: 0.2–1.2). Malondealdehyde, superoxide dismutase, catalase, glutathione S transferase, glutathione reductase and cortisol levels increased in case of L. parsia from Malancha and Chandanpiri. Succinate dehydrogenase, lactate dehydrogenase, Ca+2 ATPase and cytochrome C oxidase levels were significantly (P < 0.05) lower at Malancha and Chandanpiri than Diamond Harbour. Heat shock protein (HSP70) expression was significantly (P < 0.05) higher in all fish species at Malancha followed by Chandanpiri and Diamond Harbour. Glucose, glycogen, hexokinase, phosphofructokinase and glycogen phosphorylase levels varied between sites and selected fish species. Serum cortisol level was measured and found to be the highest in L. parsia from Malancha (2.94 ± 0.12 ng/ml) and the lowest in M. gulio from Diamond Harbour (0.7 ± 0.05 ng/ml). The results indicate that metal toxicity alters antioxidant levels, oxidative status and energy production in fish in species specific manner. Our results also indicate that Mystus has the highest degree of adaptability in response to metal toxicity possibly due to its specific food habit and niche position. Therefore, it can be concluded that maintenance of oxidative and metabolic status to combat metal-induced oxidative load will be helpful for the fishes to acquire better resistance under such eco-physiological stress. Alteration of niche and interactive segregation in aquatic organism may be one of the key modulator of resistance against such stress.

An assessment of bird communities across Ujjani and its five satellite wetlands in Solapur District of Maharashtra, India

Ujjani wetland is a potential Ramsar site in Maharashtra, India with several satellite wetlands associated with it. The present study contributes to single large or several small habitat conservation theories by assessing wetland bird communities. Aquatic bird communities were assessed using area search and point count methods at Kumbhargaon (Ujjani), Bhadalwadi, Madanwadi, Palasdev, Pimple and Ravangaon wetlands between October 2011 and September2012. These are representative satellite wetlands around Ujjani. One-hundred-and-ten species of wetland birds across 12 orders and 29 families were recorded. Out of these, 66 were resident and 44 were found to be migrants. These birds represent 23% mudflat feeder, 16% upland feeder, 14% marsh feeder, 12% bird of prey, 11% surface feeder and fish eaters, while divers and wet meadow feeders were represented with 8.5% and 5% of the species, respectively. Among the birds recorded, Woolly-necked Stork Ciconia episcopus, Common Pochard Aythya farina, and Greater Spotted Eagle Clanga clanga belong to the Vulnerable category; while Eurasian Curlew Numenius arquata, Oriental Darter Anhinga melanogaster, Black-tailed Godwit Limosa limosa, Black-headed Ibis Threskiornis melanocephalus, Lesser Flamingo Phoeniconaias minor, Painted Stork Mycteria leucocephala, River Tern Sterna aurantia, and Great Thick-knee Esacus recurvirostris represent Near Threatened category on the IUCN Red List. The presence of these bird species underlines the importance and conservation priorities of a major as well as smaller satellite wetlands. Anthropogenic activities such as cattle grazing, fishing, sand and soil mining, land encroachment, urban development and tourism were observed as some of the threats to this wetland ecosystem as well as bird communities.&#x0D;

Comparison of Growth, Proximate and Minerals Composition of Commonly Polycultured Fish Species by Replacing Surface Feeder Fish

Comparison of Growth, Proximate and Minerals Composition of Commonly Polycultured Fish Species by Replacing Surface Feeder Fish

Self-foraging vs facilitated foraging by Lesser Black-backed Gull (Larus fuscus) at the Frisian Front, the Netherlands

The Lesser Black-backed Gull, Larus fuscus Linnaeus, 1758, is a surface feeder with a broad prey spectrum that forages in the North Sea on subsurface pelagic fishes and crabs swimming within 0.6 m of the sea surface. In July 2006 and in July/August 2009, we surveyed the Frisian Front area in the southern North Sea (53.4°N–54.3°N, 4.0°E–5.5°E) to determine the prey base for Lesser Black-backed Gulls. In July/August 2009, we conducted bird counts in an integrated ecosystem survey by simultaneously sampling subsurface pelagic prey by a combination of fishing and echosounding. Lesser Black-backed Gulls make use of facilitated foraging to improve the catchability of their prey. The two most important aids for facilitated foraging by Lesser Black-backed Gull in the Frisian Front were (1) multispecies feeding associations with Common Murre, Uria aalge (Pontoppidan, 1763), and (2) fisheries discarding bycatch and offal. We found that in the top meter of the water column, the natural prey base is large enough to provide for self-foraging; however, Lesser Black-backed Gulls were found to rely mainly on facilitated foraging.

Does solar heated structure mimicking greenhouse effective to impede winter growth reduction of some tropical fishes?

Winter reduction of fish growth is one of the major concerns in aquaculture. Using the principle of greenhouse mediated raised temperature, the issue has been addressed by examining the growth responses of some tropical fishes in polyculture (rohu, mrigal, bata, Japanese punti, grass carp, common carp, magur, freshwater prawn) and two stocking ratios (80:20 and 20:80) with surface and column feeder (catla, silver carp, rohu, Japanese punti and bata) and bottom feeder (mrigal and common carp). Advanced fry of these fishes were introduced separately in solar heated greenhouse and in open polyhouse (13 × 1.5 × 2 m3) placed in triplicate in a pond and reared for 120 or 98 days during the winter for two consecutive years. The rate of survival (20–83%) and net weight gained by different species of fish were distinctly higher in closed set up (0.22–2.95 g/day) than in open (4–66%; 0.11–1.80 g/day) ones in both trials. Among the species, warmth induced net weight gain was maximal for Japanese punti (196 g), followed by rohu (159 g), mrigal (115 g), grass carp (104 g), bata (36 g) and freshwater prawn (28 g) in polyculture. The frequency distribution of harvested fishes was skewed towards large fishes in solar heated greenhouse and smaller ones in open units. Water temperature ranged from 21.6–28.1 °C and 17.2–23.7 °C in the closed and open units, whereas mean temperature remained 4.5–5 °C higher in the former than in latter. There was no marked differences in total alkalinity (219–231 mg/l), inorganic carbon (289–417 mg/l), organic carbon (4.27–4.52 mg/l), dissolved oxygen (6.61–6.75 mg/l), total dissolved solids (420.48–423.74 mg/l) and conductivity (549.83–563.29 μs/cm) between the closed and open enclosures, and remained within the range for fish culture. The score values of the sum total of the integrated ecological conditions revealed that ~ 5 °C rise in water temperature during winter enhanced as high as 36% increased yield of fish (2546 kg/ha) over open units mediated through microbial driven augmented manure mineralization leading to increased primary productivity, zooplankton abundance and ecological integrity. In essence, the solar heated greenhouse would be of considerable use for circumventing the retarded growth during winter in tropical fishes.

Predictors of Ocular Surface Squamous Neoplasia and Conjunctival Squamous Cell Carcinoma among Ugandan Patients: A Hospital-based Study.

AIM:The aim of the study was to assess the predictors of ocular surface squamous neoplasia (OSSN) and conjunctival squamous cell carcinoma (SCC) among Ugandan patients.MATERIALS AND METHODS:Patients presenting for removal of ocular surface lesions received human immunodeficiency virus (HIV) testing, completed questionnaires about demographic, behavioral, and historical potential risk factors for conjunctival neoplasia, and had lesions examined for interpalpebral versus other locations, rough versus smooth texture, and number of feeder vessels. Biopsies were classified pathologically using standard definitions classified OSSN and SCC. HIV rates were calculated for patients: with OSSN, SCC, and benign lesions. Potential risk factors and gross findings were tested for abilities to predict OSSN and SCC.RESULTS:One hundred and ninety-five patients presented with 212 lesions in 203 eyes. Nearly 34% of the patients were more than 60 years old, 67% were peasants, 88% spent more than 20 h/week outdoors, and only 10% wore sun protection. No potential risk factors predicted neoplasia. HIV prevalence was 17.1% among patients with OSSN compared to 11.1% among those without OSSN; 42.9% among SCC patients compared to 12.0% among those without SCC. Rough tumor surface (adjusted odds ratio [aOR] = 4.4 and 95% confidence interval [CI]: 2.2–9.1), six or more feeder vessels (aOR = 2.6, 95% CI: 1.3–5.2), and interpalpebral tumor location (aOR = 3.3, 95% CI: 1.5–7.1) predicted OSSN. Only a rough tumor surface (aOR = 34.6, 95% CI: 7.8–153.4) predicted SCC.CONCLUSION:HIV infection remained a risk factor for OSSN and particularly, SCC, but less so than in the past. Lesions' rough surface, six or more feeder vessels, and interpalpebral location increased OSSN risk. Only a rough tumor surface increased risk for SCC.

The use of computer image analysis in determining material flow in the roller press compacting unit during compacting of fine-grained material

Mechanisms of fine-grained material flow in a roller press are a constant subject of research. The proper transfer of feed in the feeder has a significant influence on the correct course of the compaction and consolidation process, product quality, and the intensity of wear of the forming components. A few mathematical models of compaction process have been put forth, but they are focused mainly on loads in the compacting unit and consolidated material properties. During compaction the loose material properties including the Young module, the external and internal friction coefficient, and the side pressure coefficient change continuously. Therefore visualisation tests were carried out to survey the flow of material in a compaction unit equipped with rollers with a flat working surface and gravity feeder. Using the NI Vision Builder program, the recorded video observations were analyzed and the medium speed distribution of the material in the feeder was determined. The results were presented in the form of graphs and compared with one another, specifying the relationship between the material speed distribution and the press operation parameters.

Protist predation can select for bacteria with lowered susceptibility to infection by lytic phages

BackgroundConsumer-resource interactions constitute one of the most common types of interspecific antagonistic interaction. In natural communities, complex species interactions are likely to affect the outcomes of reciprocal co-evolution between consumers and their resource species. Individuals face multiple enemies simultaneously, and consequently they need to adapt to several different types of enemy pressures. In this study, we assessed how protist predation affects the susceptibility of bacterial populations to infection by viral parasites, and whether there is an associated cost of defence on the competitive ability of the bacteria. As a study system we used Serratia marcescens and its lytic bacteriophage, along with two bacteriovorous protists with distinct feeding modes: Tetrahymena thermophila (particle feeder) and Acanthamoeba castellanii (surface feeder). The results were further confirmed with another study system with Pseudomonas and Tetrahymena thermophila.ResultsWe found that selection by protist predators lowered the susceptibility to infections by lytic phages in Serratia and Pseudomonas. In Serratia, concurrent selection by phages and protists led to lowered susceptibility to phage infections and this effect was independent from whether the bacteria shared a co-evolutionary history with the phage population or not. Bacteria that had evolved with phages were overall more susceptible to phage infection (compared to bacteria with history with multiple enemies) but they were less vulnerable to the phages they had co-evolved with than ancestral phages. Selection by bacterial enemies was costly in general and was seen as a lowered fitness in absence of phages, measured as a biomass yield.ConclusionsOur results show the significance of multiple species interactions on pairwise consumer-resource interaction, and suggest potential overlap in defending against predatory and parasitic enemies in microbial consumer-resource communities. Ultimately, our results could have larger scale effects on eco-evolutionary community dynamics.

Residues of Aliphatic and Polycyclic Aromatic Hydrocarbons in Some Fish Species of Lake Temsah, Ismailia, Egypt: An Analytical Search for Hydrocarbon Sources and Exposure Bioindicators

ABSTRACTResidues of aliphatic and polycyclic aromatic hydrocarbons (PAHs) were monitored in some fish species collected from Temsah Lake, near Ismailia, Egypt. Fish were selected to represent different feeding habits and ecological niches in the lake's ecosystem. Fish samples were extracted using organic solvents, and residues of aliphatic and PAHs were separated using column chromatography and detected using gas liquid chromatography. Fish species were Clupea sirm, Mugil sehli, Mugil capito, Morone labrax, and Sciasna sp. Clupea sirm, a surface feeder fish had the highest concentration of aliphatic hydrocarbons, 320 ± 54 ng g−1, while Morone labrax, a predatory fish that live in the water column, had the highest concentration of PAHs, 315.87 ± 46 ng g−1. Even-number aliphatic hydrocarbons were more frequently detected in all fish species in comparison to odd-number aliphatic hydrocarbons, suggesting a petrogenic origin of these compounds. Meanwhile, the pattern of PAHs detected in the present study suggested that they originate from atmospheric deposition rather than land-based runoff. Morone labrax fish and Clupea sirm fish were the most suitable candidate bioindicators of exposure to aliphatic hydrocarbons and PAHs through fish consumption of the five fish species examined in this study.