PACNav: a collective navigation approach for UAV swarms deprived of communication and external localization.

This article proposes Persistence Administered Collective Navigation (PACNav) as an approach for achieving the decentralized collective navigation of unmanned aerial vehicle (UAV) swarms. The technique is based on the flocking and collective navigation behavior observed in natural swarms, such as cattle herds, bird flocks, and even large groups of humans. As global and concurrent information of all swarm members is not available in natural swarms, these systems use local observations to achieve the desired behavior. Similarly, PACNav relies only on local observations of the relative positions of UAVs, making it suitable for large swarms deprived of communication capabilities and external localization systems. We introduce the novel concepts ofpath persistenceandpath similaritythat allow each swarm member to analyze the motion of other members in order to determine its own future motion. PACNav is based on two main principles: (a) UAVs with little variation in motion direction have highpath persistence, and are considered by other UAVs to be reliable leaders; (b) groups of UAVs that move in a similar direction have highpath similarity, and such groups are assumed to contain a reliable leader. The proposed approach also embeds a reactive collision avoidance mechanism to avoid collisions with swarm members and environmental obstacles. This collision avoidance ensures safety while reducing deviations from the assigned path. Along with several simulated experiments, we present a real-world experiment in a natural forest, showcasing the validity and effectiveness of the proposed collective navigation approach in challenging environments. The source code is released as open-source, making it possible to replicate the obtained results and facilitate the continuation of research by the community.

The impact of COVID-19 on tertiary educational institutions and students in Bangladesh.

The COVID-19 forced to transform face-to-face mode of teaching to virtual in educational institutions around the globe that not only impact institutional stakeholders, but also posed as a threat to entire humanity because, all parties related to education had to change their activities. The intentions of this study therefore firstly, to determine the content analysis by interviewing tertiary students and secondly, to determine the frequency distribution by questionnaire developed from results of the content analysis. To better understand the consequences of this outbreak, we took an interview from forty respondents, including undergraduate and postgraduate students across Bangladesh. Results of Content analysis revealed that stakeholders of tertiary education are encountering severe problems in mental health, financial, technical, and study. A questionnaire was designed based on results were obtained through content analysis and distributed using email, WhatsApp, LinkedIn, Telegram, Facebook, and Instagram from May 20 to May 30, 2021. A total number of 505 valid questionnaires were received from respondents. Frequency distribution analysis disclosed that 60% respondents have no separate reading rooms. Laptops and desktops are commonly used for online classes, but unfortunately, 21% respondents have no personal electronic gadgets. Moreover, 55% reported spending less time to study during the coronavirus outbreak. Furthermore, 88% respondents reported experiencing mental health-related stress, anxiety, and depression problems. The proportion that suffered financial crisis, family disruptions, internet and technology related problems were 79%, 83% and 72% respectively. Since coronavirus pandemic is a totally new phenomenon in the world, not much empirical literature exist. So we fill the gap, investigating the issue empirically using content and frequency distribution analysis. Policy implications and recommendations are discussed accordingly.

Electric field detection as floral cue in hoverfly pollination.

Pollinators can detect the color, shape, scent, and even temperature of the flowers they want to visit. Here, we present the previously unappreciated capacity of hoverflies (Eristalis tenax and Cheilosia albipila) to detect the electric field surrounding flowers. Using hoverflies as key dipteran pollinators, we explored the electrical interactions between flies and flowers-how a hoverfly acquired a charge and how their electrical sensing ability for target flowers contributed to nectar identification and pollination. This study revealed that rapid variations in a floral electric field were related to a nectar reward and increased the likelihood of the fly's return visits. We found that thoracic hairs played a role in the polarity of hoverfly charge, revealing their electro-mechanosensory capability, as in bumblebees (Bombus terrestris). Electrophysiological analysis of the hoverfly's antennae did not reveal neural sensitivity to the electric field, which favors the mechanosensory hairs as putative electroreceptive organs in both species of hoverflies.

Manure storage operations mitigate nutrient losses and their products can sustain soil fertility and enhance wheat productivity.

Livestock manure is a valuable source of nutrients for plants. However, poor handling practices during storage resulted in nutrient losses from the manure and decrement in its nitrogen (N) fertilizer value. We explored the influence of divergent storage methods on manure chemical composition, carbon (C) and N losses to the environment as well as fertilizer value of storage products after their application to the wheat. Fresh buffalo manure (FM) was subjected to different storage operations for a period of ∼6 months, (i) fermentation by covering with a plastic sheet (CM) (ii) placed under the roof (RM) (iii) heap was unturned (SM) to remain stacked at an open space and (iv) manure heap turned monthly (TM) to make compost. During storage, 8, 24, 45 and 46% of the initial Ntotal was lost from CM, RM, SM, and TM, respectively. The respective C losses from these treatments were 16, 34, 47 and 44% of the initial C content. After stored manures application to the wheat crop, mineral N in the soil remained 27% higher in CM (14.1 vs. 11.1 kg ha-1) and 3% (10.8 vs. 11.1 kg ha-1) lower in SM compared to FM treatment. In contrast, microbial biomass C and N was 35 (509 vs.782 mg C kg-1 soil) and 25% (278 vs.370 mg N kg-1 soil) lower in CM than FM treatment, respectively indicating lower N immobilization of CM in the soil. These findings could result in the highest grain yield (5166 kg ha-1) and N uptake (117 kg ha-1) in CM and the lowest in SM treatments (3105 and 61 kg ha-1, respectively). Similarly, wheat crop recovered 44, 15 and 13% N from CM, TM and SM, respectively. Hence, management operations play a critical role in conserving N during storage phase and after stored manure application to the field. Among the studied operations, storing animal manure under an impermeable plastic sheet is a much better and cheaper option for decreasing N losses during storage and improving wheat yield when incorporated into the soil. Therefore, by adopting this manure storage technique, farmers can improve the agro-environmental value of animal manure in Pakistan.

Evaluating intraocular pressure-lowering solutions for the treatment of open-angle glaucoma: comparison between bimatoprost 0.03% and bimatoprost 0.01% - an observational switch study.

PURPOSE: The purpose of this study is to evaluate the intraocular pressure (IOP)-lowering efficacy of bimatoprost 0.01% solution in patients with primary open-angle glaucoma (POAG), who were switched from bimatoprost 0.03% solution, compared to patients with POAG who continued on bimatoprost 0.03% solution. METHODS: A retrospective review evaluated 35 patients (35 right eyes [OD], 34 left eyes [OS]) who remained on bimatoprost 0.03% and 30 patients (27 OD, 30 OS) who were switched to bimatoprost 0.01% during the period January 8, 2010 to December 26, 2012. Mean IOP was measured 6 and 3 months before the switch, at switch, and 3, 6, and 12 months after the switch. Hyperemia scores were recorded before and after the switch and were compared to a picture scale. RESULTS: Mean IOP in the group that switched was 16.96±5.03 mmHg in OD and 17.67±5.33 mmHg in OS at baseline. Mean IOP postswitch to bimatoprost 0.01% solution was 17.60±4.34 mmHg in OD and 17.00±3.37 mmHg in OS. IOP was not significantly reduced in either OD or OS postswitch to bimatoprost 0.01% (P1=0.5 OD, P2=0.2 OS). The hyperemia scores improved remarkably when bimatoprost 0.03% solution was switched to bimatoprost 0.01% solution (P<0.001). CONCLUSION: To our knowledge, this is the first switch study evaluating the hypotensive efficacy and tolerability of bimatoprost in a group of patients with open-angle glaucoma. In this study comparing bimatoprost 0.03% and 0.01% solution, we found improved tolerability postswitch to 0.01% from 0.03% bimatoprost, similar efficacy between the two concentrations before and after switch in the same patient population, and similar IOPs comparable to nonswitch bimatoprost 0.03% solution.

Association of Interleukin-6 and Myeloperoxidase with Insulin Resistance in Impaired Fasting Glucose Subjects.

Impaired fasting glucose (IFG) is a high risk subclinical condition for the progression of type 2 diabetes mellitus and the hyperglycemia seen in this condition is because of the development of insulin resistance (IR). Obesity, inflammation, oxidative stress and many other factors have been implicated in development of IR in type 2 diabetes mellitus and its successive complications. Current study was aimed to ascertain the correlation of inflammation and oxidative stress markers [interleukin-6 (IL-6) and myeloperoxidase (MPO)] with IR in subjects with IFG. In this study, 80 subjects (40 IFG, 40 healthy controls) aged 25-45 years were selected based on their fasting plasma glucose (FPG) values and clinical history. Serum insulin, IL-6 and MPO were estimated by ELISA method and IR was calculated using Homeostatic Model Assessment Index 2 (HOMA 2) calculator. Pearson's correlation coefficient and independent sample 't' test were used for statistical analysis. IL-6 and MPO were found to be significantly elevated in IFG group and both correlates significantly with IR (r 0.413, r 0.645). Only MPO had significant correlation with FPG (r 0.388). In conclusion, the association of altered levels of IL-6 and MPO with IR are suggestive of a role of inflammation and oxidative stress in the initiation and progression of IR in individuals with IFG.

Association of Serum Selenium, Zinc and Magnesium Levels with Glycaemic Indices and Insulin Resistance in Pre-diabetes: a Cross-Sectional Study from South India.

A growing understanding of antioxidant mechanisms and insulin-like actions of trace elements selenium and zinc has rekindled researchers' interest towards their role in diabetes mellitus, nutritional management of which concentrates predominantly on macronutrient intake. However, selenium studies limiting largely to diabetes have yielded inconsistent results with sparse knowledge in the pre-diabetes population. This hospital-based cross-sectional study screened 300 people who came to the institutional hospital laboratory with fasting plasma glucose and glycosylated haemoglobin requisition over a period of 6 months. Thirty-five pre-diabetes subjects aged 25-45 years and 35 age-matched healthy controls were selected as per inclusion criteria and clinical history. Serum selenium was estimated by inductively coupled plasma-mass spectrometry, zinc and magnesium by colorimetric end-point methods and insulin by enzyme-linked immunosorbent assay, and insulin resistance was calculated using a homeostasis model assessment (HOMA) 2 calculator. Data analysis was done using SPSS ver. 16 employing an independent sample t test for intergroup comparison of means and Pearson's correlation for correlation analysis. Serum mineral levels in the pre-diabetes group (selenium 63.01 ± 17.6 µg/L, zinc 55.78 ± 13.49 µg/dL, magnesium 1.37 ± 0.38 mg/dL) were significantly reduced (p < 0.05) in comparison to the healthy controls (selenium 90.98 ± 15.81 µg/L, zinc 94.53 ± 15.41 µg/dL, magnesium 2.12 ± 0.22 mg/dL). A significant negative correlation was seen with glycaemic indices and insulin resistance. This study conducted in pre-diabetes subjects highlights a considerable deficiency of serum selenium, zinc and magnesium observed at a much earlier pre-clinical phase. This coupled with the evidence of a strong inverse association with glycaemic indices and insulin resistance postulates the role of mineral alterations in the pathophysiology of hyperglycaemia and insulin resistance.

Cord Blood Insulin Levels: It's Correlation with Gender, Birth Weight and Placental Weight in Term Newborns.

The cause of more insulin resistance in female than males are still unknown. To know the cause from early life, normal values of relevant parameters are required. So, aim of this study was to determine the reference levels of glucose and insulin in cord blood of term newborns and to examine their effects on gender, placental and birth weight of term newborns. In cross sectional study 60 consecutive term newborns were included from constituent hospitals. Placental and birth weights were measured and cord blood was collected for estimation of serum insulin and plasma glucose. Plasma glucose estimation was done by auto analyzer (GOD-POD method) and serum insulin analysis was done using Insulin ELISA Kit. After analysis, mean ± 2SD used for estimating cord blood insulin and glucose levels, which were 10.1 ± 7.8 µIU/mL and 67.8 ± 33.8 mg/dL respectively. Correlation of insulin with both birth weight and placental weight were r = 0.359 and 0.41 respectively; p < 0.001. Interestingly we found higher insulin levels in females as compared to male newborns in spite of having lower birth weight in them. In conclusion this study reported the levels of insulin and glucose in cord blood of term newborns. Incidentally, this is the first study as per our knowledge to report significant correlation between cord blood insulin, glucose with birth weight, placental weight and gender in south India. Female newborns had higher insulin levels than males, despite lesser birth weight can be attributed to intrinsic insulin resistance in them.

Metabolic Syndrome in Childhood: Rare Case of Alstrom Syndrome with Blindness.

Alstrom's syndrome (AS) is a rare autosomal recessive ciliopathic condition affecting 1:10,00,000 children. It's a single gene disorder of ALMS1 on chromosome 2 with multisystem involvement with cone-rod retinal dystrophy causing juvenile blindness, obesity, insulin resistance, type 2 Diabetes mellitus, hypogonadism and sensorineural hearing loss. Till now only 800 patients with this disorder has been identified so far. In this report, we describe the case of a 9-year old male boy from south India. He had been initially referred for polyphagia, polyuria, polydipsia, generalized weakness from 1 weeks. On examination he was demonstrated features suggestive of AS, including blindness, obesity, type 2 diabetes, altered lipid profile, hypogonadism, acanthosis nigricans, seborrheic dermatitis, right ear discharge and episodes of respiratory tract infections. So, diagnosis of AS is critical as it can easily be overlooked because of the many features associated with metabolic syndrome starting at age 7, a relatively early age.

Cord Blood Levels of Insulin, Cortisol and HOMA2-IR in Very Preterm, Late Preterm and Term Newborns.

INTRODUCTION: Alteration in the glucose homeostasis is still the major cause of morbidity and mortality in the newborns. Intrauterine undernutrition plays an important role in causing adult insulin resistance and diabetes but the exact cause is still unknown. AIM: To estimate the plasma glucose, serum insulin and cortisol levels at birth in newborns at different gestational age. MATERIALS AND METHODS: The present cross-sectional study conducted from December 2014 to June 2015 included 58 newborns enrolled as per the inclusion criteria and further categorized into Group I (very preterm; n=19; gestational age < 32 weeks), Group II (late preterm; n=20; gestational age between 32-37 weeks) and Group III (full term; n=19; gestational age >37 weeks) newborns. Venous Cord Blood (VCB) was collected and plasma glucose was analysed by GOD-POD (Glucose Oxidase-Peroxidase) method in auto analyser whereas serum insulin and cortisol were analysed by ELISA (Enzyme Linked Immunosorbent Assay). HOMA2-IR (Homeostatic Model Assessment) calculator was used to assess insulin resistance. All parametric data was expressed as mean±SD and analysed using ANOVA with Tukey's as the Post-Hoc test. Correlation analysis was done using Pearson's correlation co-efficient with scatter plot as the graphical representation. RESULTS: Significantly increased insulin and HOMA2-IR levels were found in group I (13.7±4.7µIU/mL and 1.6±0.58 respectively) when compared to group II (8.3±2.9µIU/mL and 0.93±0.2 respectively) and group III (8.3±2.1µIU/mL and 1.03±0.26 respectively). A positive correlation between cortisol levels and gestational age (r = 0.6, n = 58, p < 0.001) and a negative correlation between insulin and gestational age (r = -0.654, n = 58, p < 0.001) was observed in the study population. CONCLUSION: Increased levels of insulin and HOMA2-IR as seen in the very preterm newborns signify the predisposition of these newborns to development of diabetes in later stages of life. The inverse association of cortisol and insulin with gestational age suggests that cortisol could also be responsible for impaired ß cell function and insulin sensitivity.

Evaluation of Ischemia-Modified Albumin, Malondialdehyde, and Advanced Oxidative Protein Products as Markers of Vascular Injury in Diabetic Nephropathy.

AIM: This study aimed at evaluation of ischemia-modified albumin (IMA), malondialdehyde (MDA), and advanced oxidative protein products (AOPP) as markers of vascular injury in diabetic nephropathy (DN) with derivation of cutoff values for the same. MATERIALS AND METHODS: Study population comprised 60 diabetes patients and 30 controls, with diabetes patients further categorized into three groups based on urine albumin/creatinine ratio (UACR) of <30 mg/g (diabetes without microalbuminuria), 30-300 mg/g (early DN), and >300 mg/g of creatinine (overt DN). Serum IMA, MDA, and AOPP were estimated by enzyme-linked immunosorbent assay; HbA1c, serum creatinine, urine albumin, and urine creatinine were estimated using automated analyzers. Statistical analysis was done using analysis of variance, Pearson's correlation coefficient, and receiver-operating characteristic curve. RESULTS: A statistically significant difference was found in the levels of IMA among patients with early DN (154 ng/mL), diabetes without nephropathy (109.4 ng/mL), and healthy controls (45.7 ng/mL), with highest levels in early DN cases. Similar increase was seen in AOPP as well. A significant correlation was observed between IMA and UACR in diabetes without nephropathy (r = 0.448). CONCLUSION: The present study postulates serum IMA as a novel biomarker for the assessment of disease progression in diabetes even before microalbuminuria, and a cutoff point ≥99 ng/mL can be used for detection of early DN.

Serum Lactate Dehydrogenase in Non-Hodgkin's Lymphoma: A Prognostic Indicator.

Non-Hodgkin's lymphoma constitutes a group of disorders originating from the malignant transformation of lymphocytes and involving either the lymph nodes or extranodal sites. NHL commonly presents in the sixth to seventh decade of life with a male preponderance (50-75 %). Recent studies have shown importance of serum LDH in prognosis of NHL. Authors report a case of a 63 year old male presenting with complaints of fever and backache for past 4 months. General and systemic examination revealed bilateral axillary lymphadenopathy and splenomegaly respectively. Serum LDH level was highly elevated (3441 U/l). Excisional axillary and bone marrow biopsy were done before oncology referral. Complete workup revealed diffuse Non-Hodgkin's lymphoma with bone marrow infiltration. Patient died because of acute renal failure due to NHL and DM 2 (Type 2 diabetes mellitus).

Indices of Glucose Homeostasis in Cord Blood in Term and Preterm Newborns.

OBJECTIVE: According to the thrifty phenotype hypothesis, intrauterine malnutrition has a role in the etiology of type 2 diabetes. This study was planned to determine the early alterations in indices of glucose homeostasis (glucose, insulin, and cortisol) in term and preterm newborns and the correlations of glucose, insulin, and cortisol levels with insulin resistance indices. METHODS: A descriptive study comprising 35 term and 35 preterm newborns was carried out from December 2013 to June 2015. Venous cord blood was collected and plasma glucose was analyzed by the glucose oxidase-peroxidase method in an auto analyzer. Serum insulin and cortisol levels were assessed by the enzyme-linked immunosorbent assay. Homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index and glucose insulin ratio were calculated to assess insulin resistance. The data on physical and metabolic parameters were analyzed using standard tests for statistical significance. RESULTS: In term newborns, mean glucose and cortisol levels (83.6±17.4 mg/dL and 11.88±5.78 µg/dL, respectively) were significantly higher than those in preterm infants (70.4±15.8 mg/dL and 8.9±4.6 µg/dL, respectively). Insulin and HOMA-IR levels were found higher in preterm newborns (10.8±4.8 µIU/mL and 1.52±0.66, respectively) than in term newborns (7.9±2.7 µIU/mL and 1.19±0.29, respectively). Insulin was found to positively correlate with HOMA-IR, whereas cortisol was negatively correlated with HOMA-IR in both term and preterm newborns. CONCLUSION: Higher insulin levels and HOMA-IR values in the cord blood of preterm newborns support the theory of intrauterine origin of metabolic diseases.

Assessment of oxidative stress and inflammation in prediabetes-A hospital based cross-sectional study.

BACKGROUND AND AIM: Prediabetes is associated with dysglycemia, obesity, inflammation and endothelial dysfunction, contributing towards the pathogenesis of cardiovascular diseases rendering them vulnerable for the same. The current study intended to explore the risk of cardiovascular disease (CVD) related with prediabetes by assessing oxidative stress and inflammation using serum interleukin-6 (IL-6), myeloperoxidase (MPO) and urine microalbumin (MA) and their correlation with fasting plasma glucose (FPG) and physical measurements. MATERIALS AND METHODS: Based on FPG values, 80 subjects were grouped into prediabetes and healthy controls. IL-6 and MPO were estimated in serum sample whereas MA was estimated in random urine sample. RESULTS: Prediabetes group had significantly increased (p<0.05) mean anthropometric measurements and IL-6, MPO and MA as compared to healthy controls. MPO had significant correlation with FPG (r-0.388) in the prediabetes group. IL-6 and MPO showed a positive correlation with body mass index (BMI (r-0.339, r-0.327)), waist circumference (WC (r-484, r-0.493)) and waist-to-hip ratio (WHR (r-0.430, r-0.493)) while MA did not correlate with FPG and anthropometric measurements. CONCLUSION: This study suggests that prediabetes is associated with central adiposity, inflammation and oxidative stress predisposing them to an increased risk for CVD.

Long-term IOP lowering with bimatoprost in open-angle glaucoma patients poorly responsive to latanoprost.

PURPOSE: The aim of this study was to study long-term intraocular pressure (IOP) lowering following a switch to bimatoprost in patients with open-angle glaucoma (OAG) not at target IOP while on latanoprost either as monotherapy or as polytherapy with other topical adjunctive agents. METHODS: A retrospective review of OAG patients, with <20% IOP lowering from pretreatment baseline while on latanoprost either as monotherapy or in combination with adjunctive agents who were switched to bimatoprost, was conducted. Main outcome measures were mean IOP at 6, 12, and 24 months following the switch to bimatoprost and percent IOP lowering from baseline IOP before the switch. RESULTS: Records of 30 patients (30 right eyes [OD], 29 left eyes [OS]) were reviewed. Mean IOP preswitch was 23.1 +/- 4.3 mmHg in OD and 22.3 +/- 3.8 mmHg in OS. Postswitch to bimatoprost, IOP was significantly reduced (P < 0.005) at each of the time points studied and patients experienced additional IOP lowering ranging from 17.8 to 22.0% in OD and 15.0-24.0% in OS. Bimatoprost was well tolerated in all but 1 patient. CONCLUSIONS: Significant additional long-term IOP lowering may be achieved by switching to bimatoprost in patients with open-angle glaucoma who are not at target IOP with latanoprost.

Right ventricular myxoma with heart failure.

Cardiac myxomas are histologically benign tumors but they may be lethal because of their strategic position. These are mostly located in the left atrium and uncommonly in the right atrium. We report a case of a large right ventricular myxoma presenting with heart failure.

Complications of ophthalmologic nerve blocks: a review.

Complications of ophthalmologic nerve blocks are rare, but they can have serious life- and sight-threatening consequences. Knowledge of the potential complications is essential for the anesthesiologist who performs ophthalmologic nerve blocks. However, most anesthesiologists are unfamiliar with these complications because the majority have been reported in the ophthalmology literature. We review the complications that may occur during the placement of ophthalmologic blocks and their appropriate prompt treatment.

Bioactivity evaluation of Bergenia ciliata.

Bergenia ciliata was subjected to bioactivity analysis. The records of these investigations are described in this communication. A study made on the bioactivity analysis of medicinal herb Bergenia ciliata, which in folkloric medicine is used to cure hypoglycemic activity. A battery of assays was performed on different extracts of Bergenia ciliata which include hypoglycemic activities, toxic evaluations such as acute systemic and intracutaneous toxicity as well hemolysis test. Bergenia ciliata has been employed in folklore medicine to treat symptoms of diabetes mellitus. All the extracts except chloroform extract of root and leaves of Bergenia ciliata were found to possess hypoglycemic activity in Streptozotocin (STZ) treated rats. Therefore the plant can be classified as hypoglycemic, hypoglycemic activity in experimental diabetes ranging from 40-70% of its onset to reduce blood glucose level. The toxicological investigations of Bergenia ciliata with particular reference to acute systematic toxicity and intracutaneous toxicity in experimental animals displayed that it elicit severe toxicity. The symptoms of toxicity in intracutaneous test showed erythema and edema whereas assessment of acute systemic toxicity frequently observed breathing problem and initiations of diarrhea with blood in stool of experimental model and caused gastero-intestinal syndrome. Bergenia ciliata can produce toxicity suggesting a role in certain diseases. It is therefore, premature to speculate about mechanism of effect until toxin(s) is unequivocally identified. The hemolysis test on the extract of Bergenia ciliata was almost devoid of activity.

Evaluation of antibacterial activity of Bergenia ciliata.

Bergenia ciliata was subjected to antibacterial analysis. A battery of assays were performed on different extracts of Bergenia ciliata for antibacterial activities. Antibacterial effects of ethanol, hexane, ethyl acetate, chloroform, butanol and aqueous extracts of the roots and leaves extract of Bergenia ciliata exhibited various degree of inhibition activity. It was observed that root and leaves extract were promising against gram positive and gram negative bacteria viz. Bacillus subtilis, Bacillus megaterium and Pseudomonas aeruginosa. This study showed that Bergenia ciliata could inhibit selectively bacteria.