Functional development of carbon dioxide detection in the maxillary palp of Anopheles gambiae

Olfactory information drives several behaviours critical for the survival and persistence of insect pests and vectors. Insect behaviour is variable, linked to their biological needs, and regulated by physiological dynamics. For mosquitoes, CO(2) is an important cue that signifies the presence of a host, and which elicits activation and attraction. To investigate the genetic basis of olfactory modulation in mosquitoes, we assayed changes in CO(2) detection from receptor gene expression through physiological function to behaviour, associated with the onset of host seeking in the malaria vector, Anopheles gambiae. The gene encoding a subunit of the CO(2) receptor, AgGr22, was found to be significantly up-regulated in host-seeking females, consistent with a significant increase in sensitivity of CO(2)-responsive neurons (cpA) housed in capitate peg sensilla of the maxillary palp. In addition, the odorant receptor AgOr28, which is expressed in cpC neurons, was significantly up-regulated. In contrast, AgOr8, which is expressed in cpB neurons, was not affected by this change in physiological state, in agreement with results for the obligate co-receptor Orco. Moreover, the sensitivity of the cpB neuron to (R)-1-octen-3-ol, a well-known mammalian kairomone, did not change in response to the onset of host seeking. The concentration of CO(2) flux influenced both the propensity of A. gambiae to take off into the wind and the speed with which this activation occurred. Female A. gambiae mosquitoes responded to CO(2) whether mature for host seeking or not, but onset of host seeking enhanced sensitivity and speed of activation at relevant doses of CO(2)

The prevalence of glucose intolerance among antenatal clients at Kenyatta National Hospital at, 24-36 weeks of gestation

Objectives: To determine the prevalence of and associated factors for glucose intolerance among antenatal clients at Kenyatta National Hospital at 24-36 weeks of gestation.Design: Cross-sectional analytical study.Setting: Kenyatta National Hospital antenatal clinic.Subjects: One hundred and two (102) antenatal mothers at a gestational age of 24-36 weeks were recruited into the study and underwent a 100g Oral Glucose Tolerance Test (OGTT) after consenting to participate in the study.Results: From the study 37(36%) had glucose intolerance while 65 (64%) had normal glucose tolerance. Among clients with glucose intolerance, 16.7% met the diagnostic criteria for gestational diabetes, 3.9% had impaired glucose tolerance and 15.7% had impaired fasting glycaemia. Of the clients with normal glucose tolerance 22.5% displayed flat curves. Factors significantly associated with glucose intolerance were: BMI > 25;P-value 0.036: OR 0.37 CI (1.06-6.90), history of and treatment for sub-fertility p-value 0.002: OR 8.69 CI (1.74-43.50) and family history of hypertension; p-value 0.037: OR 2.66 CI (1.04-6.78).Conclusion: The prevalence of glucose intolerance was 36%. This is much higher than the 5% previously reported. There is need to screen pregnant women for glucose intolerance to prevent the complications usually associated with it

Lithopaedon Presenting as Intestinal Obstruction with a Previous Co-Existing Intra-Uterine Pregnancy

This is a case report of a 25 year old lady Para 4 + 0 gravida 5, who was referred to Kisii level 5 hospital from a district hospital with a diagnosis of intestinal obstruction and a four year history of an intra-abdominal mass. A year prior to the admission she conceived and delivered vaginally at home but the baby died a few hours after the delivery. On examination on admission there was a solid mass in the right upper quadrant. Ultrasound imaging showed a poor echo-calcified mass suggestive of a colonic metastatic mass and an erect abdominal x ray revealed foetal bones within the abdominal cavity. At laparatomy a lithopedion with a normal uterus was found. The presence of a lithopedion and a normal intra-uterine pregnancy followed by spontaneous vertex delivery has not been reported in Kenya.Patients with lithopaedon can present with intestinal obstruction as a complication but the presence of a co-existing pregnancy is rare

EFFECTS OF SEQUENTIAL TEACHING METHODS ON RETENTION OF KNOWLEDGE IN BIOLOGY BY SECONDARY SCHOOL STUDENTS IN KENYA

Despite the importance of knowledge in Biology, candidates’ performance at the national examination, The Kenya Certificate of Secondary Education (KCSE) is poor. This could be attributed to the teaching methods. The purpose of this study was to compare differential effectiveness of Sequential Teaching Methods (STM) on the, retention of knowledge in Biology by secondary school students. The study was Quasi- experimental using the Non-equivalent control- group 16 study design. The target population comprised students in the 18 old category National Schools in Kenya that were in existence before 2012. Purposive sampling was used to obtain a sample of eight (8) schools and 402 Students. The students in the eight (8) sub-groups were taught the same Biology topic: “General Characteristics of Enzymes”, using different sequences of three teaching methods namely: lecture, slide demonstration and laboratory (student experiment). Group I (ELD) began with experiments, followed by lecture method and was lastly shown, animated slides. The sequence of the three different methods used in the first group was altered in both the second and third groups as follows: The lecture method, slide demonstration and laboratory experiment (LDE) for Group II, and slide demonstration, experiment and lecture method (DEL) for group III. Students in group IV (control group) were taught using (oral-only) lecture method. The teachers gave lectures and performed slide demonstration   while the students carried out laboratory experiments. The test was used as a pre-test and also as a retention test that was administered 40 days after the Post-test BAT. This test had 25 objective questions testing knowledge of facts, application of knowledge and problem solving ability. To measure Retention of Knowledge, the researcher used Biology Retention Test (BRT). The research hypothesis was tested using ANOVA at significant level of 0.05. The results and findings of the study show that STM, when efficiently used in instruction, enhance immediate retention of knowledge in Biology more effectively than the oratory lecture method predominantly used in Kenyan Secondary schools. Furthermore, DEL sequence was identified as the most effective in comparison to LDE and ELD. The findings of the study will help curriculum developers and teachers to choose the most appropriate sequence to use in Biology.  Article visualizations

Towards hardware acceleration of neuroevolution for multimedia processing applications on mobile devices

This paper addresses the problem of accelerating large artificial neural networks (ANN), whose topology and weights can evolve via the use of a genetic algorithm. The proposed digital hardware architecture is capable of processing any evolved network topology, whilst at the same time providing a good trade off between throughput, area and power consumption. The latter is vital for a longer battery life on mobile devices. The architecture uses multiple parallel arithmetic units in each processing element (PE). Memory partitioning and data caching are used to minimise the effects of PE pipeline stalling. A first order minimax polynomial approximation scheme, tuned via a genetic algorithm, is used for the activation function generator. Efficient arithmetic circuitry, which leverages modified Booth recoding, column compressors and carry save adders, is adopted throughout the design

Secure pseudo-random linear binary sequences generators based on arithmetic polynoms

We present a new approach to constructing of pseudo-random binary sequences (PRS) generators for the purpose of cryptographic data protection, secured from the perpetrator's attacks, caused by generation of masses of hardware errors and faults. The new method is based on use of linear polynomial arithmetic for the realization of systems of boolean characteristic functions of PRS' generators. "Arithmetizatio" of systems of logic formulas has allowed to apply mathematical apparatus of residue systems for multisequencing of the process of PRS generation and organizing control of computing errors, caused by hardware faults. This has guaranteed high security of PRS generator's functioning and, consequently, security of tools for cryptographic data protection based on those PRSs

2,6-Bis(tosyl­oxymeth­yl)pyridine

The title compound, C21H21NO6S2, is organized around a twofold axis parallel to the crystallographic c axis and containing the N atom and a C atom of the pyridine ring. The tosyl moiety and the pyridine ring are both essentially planar [maximum deviations 0.028 (2) and 0.020 (3) Å, respectively]; their mean planes form a dihedral angle of 33.0 (2)°

Weed Dynamics during Transition to Conservation Agriculture in Western Kenya Maize Production

Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize intercropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean harvest (RELAY) and maize, bean and mucuna planted in a strip intercropping arrangement (STRIP). Herbicides were used in NT, shallow hand hoeing and herbicides were used in MT and deep hoeing with no herbicides were used in CT. Weed and maize performance in the maize phase of each cropping system were assessed at both locations and costs of weed control were estimated at Manor House only. Weed density of grass and forb species declined significantly under MT and NT at Manor House and of grass species only at Mabanga. The greatest declines of more than 50% were observed as early as within one year of the transition to MT and NT in STRIP and TYPICAL cropping systems at Manor House. Transitioning to conservation based systems resulted in a decline of four out of five most dominant weed species. At the same time, no negative impact of MT or NT on maize growth was observed. Corresponding costs of weed management were reduced by $148.40 ha-1 in MT and$149.60 ha-1 in NT compared with CT. In conclusion, farmers can benefit from effective and less expensive weed management alternatives early in the process of transitioning to reduced tillage operations

NATURE OF FRAUD AND ITS EFFECTS IN THE MEDICAL INSURANCE SECTOR IN KENYA

ABSTRACT Insurance fraud is a major challenge facing the insurance industry both in thedeveloping and developed world. This vice has no doubt existed wherever insurance policies areunderwritten and takes different forms depending on the economic time and coverages available.However, the validity of this claim has hardly been established empirically in Kenya. It is importantthat the insurance players in Kenya understand the nature and effects of insurance fraud and alsocome up with strategies to counter the same. The study objective was to investigate the nature offraud and its effects in the medical insurance sector in Kenya and also establish possible solutionsin countering the vice. The study adopted a descriptive research design where each of the twentyeight registered medical insurance providers and twenty Insurance companies underwritingmedical insurance in Kenya formed the sample frame of forty eight firms. A questionnaire was themain research instrument. The study findings revealed that majority of the firms sampled hadexperienced different levels of fraud in the recent past with the fraud form ranging from overstatedmedical bills, concealment of medical history of the patient, fraudulent identity / impersonation,document theft fraud as well as perpetration of the insurance premium fraud. The extent of fraudwas found to depend on the existence and extent of automation that the firms had adopted with highfraud levels being associated with low IT Usage and/or automation. The effects of fraud include:increase in the cost of medical insurance and tarnishing the image of the insurance industry.Solutions suggested in manageing the level of fraud include: subjecting medical bills to extensiveaudit to determine their validity as well as high levels of automation of the processes, making itmandatory for clients to produce their smart-cards in any medical facility before receiving services,and maintaining a database of all insured within the organizations’ network. Other strategiesinclude restriction of unauthorized employees in accessing client information, educating the staff touphold ethical practices and offering a better remuneration and friendlier work environment. Thisstudy contributes to a partial understanding of the reasons for medical covers being expensive andthe negative image of the insurance industry

Assessment of community led total sanitation uptake in rural Kenya

Background: Community Led Total Sanitation (CLTS) is an innovative community led drive to set up pit latrines in rural Kenya with an aim of promoting sustainable sanitation through behaviour change. It’s a behaviour change approach based on social capital that triggers households to build pit latrines without subsidy. The Ministry of Health introduced the CLTS campaign in 2007 and the first road map to ODF ended in 2013. Since the commencement of the CLTS Programme in, there is little documentation on assessment of its uptake from triggering to the certification of open defecation free villages.Objective: To assess the magnitude of Community Led Total Sanitation (CLTS) triggering to certification of Open Defecation free (ODF) villages in rural Kenya.Design: A retrospective descriptive study.Setting: The 47 counties in Kenya. Kenya is projected to have a population of 46 million people with the majority as rural populace. The study unit were Villages across the 47 counties from the data generated in the CLTS monitoring and evaluation dataset.Results: The number of triggered villages (11641) compared to those that reached certification stage (3131) reduced significantly. Busia County achieved the 100% target for triggering. There was a significant decline of the proportions per county in the process of claiming, verifying and certifying ODF villages however Busia, Siaya and Vihiga were leading across the counties. The proportion of CLTS facilitators and CLTS certified villages per county were incongruent.Conclusion: There was low uptake of CLTS from the triggering phase to the certification phase due to plausible factors such as inadequate monitoring of the CLTS process, inadequate funding of CLTS programmeming and conflicting work demands on the CLTS facilitators leading to reduced momentum as observed in Uganda