Analiza utjecaja faktora rizika na pojavnost subkliničkog mastitisa na nekim farmama mliječnih krava na istoku Alžira

In order to study the effect of various risk factors on the prevalence of subclinical mastitis, we studied the prevalence of subclinical mastitis in 104 dairy cows (416 udders) from 18 bovine herds in three wilayas in eastern of Algeria using the California mastitis test (CMT) combined with bacteriological analysis. The aim of this research was to determine the effect of 27 risk factors related to the animal, its environment and milking practices on prevalence, as well as the effects of breed, age, stage of lactation, housing and litter type, hygiene level, season, mil production, vacuum level and elimination of first jets on subclinical mastitis frequency. A survey was carried out to collect data on cow numbers, breeds, type of breeding, housing, litter and the level of hygiene in farms, the method of milking and milking practices. The CMT combined with bacteriological examination was performed to detect subclinical mastitis, the Chi 2 test was used to test for difference between the means. Prevalence values were: 24% by CMT vs 17% by bacteriology analysis. Concerning udders, we recorded a rate of 10% vs. 8.7% respectively. The results of the survey show that the Holstein breed is the most exploited and affected (P<0.05). The number of dairy cows varied from 3 to 20 cows. In this study, 56% of cows were raised on farms built of cinder blocks, which had a lower rate compared to farms built of wood and reeds (P<0.001). Animal housing consisting of a concrete floor 33% vs. 36% raised with straw bedding and were more affected (P<0.001), litter is removed only once a day for 13% of cows, which is a factor that predisposes cows to this disease. The frequency is higher during early and late compared to mid-lactation phases (P<0.05); low udder conformation and the right side of udders also had an impact on this disease alongside animal hygiene (P<0.05), and cattle producing more than 12 litres per day were more susceptible (P<0.05). However, the frequency of mastitis was only slightly modified by the lactation number of cows. High and low vacuum level of milking machines and pulsation frequency predisposed cows more to this disease (P<0.05). In this study, cows milked manually were significantly more affected (P<0.05) particularly in summer and the winter, showing high rates (P<0.05).Da bismo uočili učinak različitih faktora rizika na prevalenciju subkliničkog mastitisa, ispitali smo prevalenciju subkliničkog mastitisa u 104 (416 vimena) mliječnih krava iz 18 stada goveda koja se uzgajaju u tri provincije (wilaya) u istočnom Alžiru. Ispitivanje smo proveli pomoću kalifornijskog testa za mastitis (CMT) u kombinaciji s bakteriološkom analizom. Cilj je ovog istraživanja bio utvrditi učinak 27 faktora rizika povezanih sa životinjama, njihovim okolišem i praksom mužnje na prevalenciju, kao i učinak pasmine, dobi, faze laktacije, vrste staje i stelje, razine higijene, godišnjeg doba, proizvodnje mlijeka, razine vakuuma i eliminacije prvih mlazova na učestalost subkliničkog mastitisa. Provedena je anketa u svrhu prikupljanja podataka o broju krava, eksploatiranim pasminama, vrsti uzgoja, staje, stelje i razini higijene na farmama, metodi mužnje i praksom mužnje. Proveden je CMT test u kombinaciji s bakteriološkim testiranjem za detekciju subkliničkog mastitisa. Chi 2 test je rabljen da bi se provjerila razlika između sredstava. Vrijednosti prevalencije bile su: 24 % prema CMT-u u usporedbi sa 17 % prema bakteriološkoj analizi. U svezi s vimenima, zabilježili smo stopu od 10 % u usporedbi s 8,7 %. Rezultati ankete pokazali su da je holstein pasmina najeksploatiranija i najviše zahvaćena (P<0,05); broj mliječnih krava varira od 3 do 20 krava. U ovoj studiji 56 % krava uzgajano je na farmama izgrađenima od opeke i one su imale najniže stope mastitisa u usporedbi s farmama izgrađenima od drva i trske (P<0,001). Staje za životinje imaju betonski pod za 33 % (životinja) u usporedbi s 36 % uzgajanih na podlozi od slame koje su bile više zahvaćene (P<0,001); stelja se podiže jednom na dan za 13 % krava, a to je uvjetovalo krave na ovu bolest. U usporedbi sa sredinom laktacije (P<0,05) učestalost je veća u ranoj i kasnoj laktaciji, niska morfologija vimena i desna strana vimena su utjecale su i na ovu bolest, uz higijenu životinja (P<0,05). Krave koje su proizvodile više od 12 L/dan bile su prijemčivije na bolest (P<0,05). Međutim, učestalost mastitisa malo je modificirana brojem laktacija krava. Visoki i niski vakuum strojeva za mužnju, učestalost impulsa više je uvjetovalo krave na ovu bolest (P<0,05). U ovoj studiji, krave koje su ručno mužene značajno su više bile pogođene ovom bolesti (P<0,05), posebice ljeti i zimi, pokazujući veće stope bolesti (P<0,05)

Influence of Three Probiotics Strains, Lactobacillus rhamnosus GG, Bifidobacterium animalis subsp. Lactis BB-12 and Saccharomyces boulardii CNCM I-745 on the Biochemical and Haematological Profiles and Body Weight of Healthy Rabbits

Currently, probiotics are used as growth promoters on a large scale to improve the productivity of several animals’ species within the aim of reducing the presence of antibiotic residues in animal products consumed by humans. Several reports evidenced the positive effect of probiotic supplementation on the growth performances and health of rabbits, mainly through the balance of the intestinal microbiota of the host animal. Therefore, certain probiotics, including Lactobacilli, Bifidobacteria, Saccharomyces, can improve the biochemical and haematological profiles, especially in production animals. In this context, this study was performed on rabbits for the economic importance they play as a source of meat proteins in developing countries and their use as experimental models in research and biomedicine. This study then aimed to evaluate the effect of three strains of probiotics: Lactobacillus rhamnosus GG Bifidobacterium animalis subsp. Lactis BB-12 and Saccharomyces boulardii CNCM I-745, on the biochemical and haematological parameters and their influence on the rabbit’s weight of the ITELV2006 strain. The findings evidenced that the probiotic strain affected the biochemical and haematological parameters. Further, the strains showed a positive effect on the weight gain of the rabbits.This study aimed to investigate the effects of three strains of probiotics, these being Lactobacillus rhamnosus GG, Bifidobacterium animalis subsp. Lactis BB-12 and Saccharomyces boulardii CNCM I-745, on the body weight, animal performances and blood parameters of rabbits (male and female) of the ITELV2006 strain. The supplementation of the feed of the rabbits with the three probiotic strains allowed observing positive effects on most of the biochemical and haematological parameters investigated during a period of 60 days (30 days of supplementation and 30 days without treatment). Further, there was a significant improvement in the body weight of the rabbits at the end of the experiment. The effect of the three probiotics investigated in this trial was found to be related to the sex of the rabbits and to the intake period (duration). Ultimately, these findings raise the possibility of using probiotics to investigate in an in-depth and specific manner based on fixed factors such as the strain, the gender and age of the animals, the main underlying mechanisms and effects, which would allow achieving optimal and adapted health benefits and sustainable production. In the context of animal production, it is worth investigating in a targeted study the effect of the three strains on muscle growth and development and finding evidence of the possible consequences on meat quality traits of the rabbits supplemented with probiotics

Preliminary investigation of the antimicrobial and mechanisms of resistance of Enterobacteria isolated from minced meat in the Northeast of Algeria: The case of butchers from Constantine

peer-reviewedFood products of animal origin such as fresh meat are easily contaminated by microorganisms if handling, processing and storage conditions are not fully respected. The present study aimed first to evaluate the bacterial load and microbial contamination rates of ground raw beef to identify the main pathogenic flora that dominate and second, to determine the resistance patterns and extended-spectrum beta-lactamase (ESBL) of isolated Gram-negative strains against certain families of antibiotics. Therefore, 39 samples have been collected from 5 butcher shops located in Constantine province in the North-East of Algeria. The samples were analysed for total bacterial count, presence of total and faecal coliforms, Staphylococci and Salmonella. Furthermore, 23 antibiotics were tested using the diffusion method on Mueller-Hinton agar, towards 22 strains isolates. Bacterial analyses showed a high contamination by total aerobic bacteria, total and faecal coliforms. Escherichia coli, Citrobacter spp., Enterobacter spp., Hafnia alvei, Salmonella pullorum and Staphylococcus spp (except Staphylococcus aureus) were further revealed in some samples. The results of the antibiogram test exhibit multi-resistance to more than eight antibiotics with varied effects. From the whole tested strains isolates, the fully susceptibility effect was for spectinomycin (SPT). This study reveals that the analysed minced meat was found to be highly contaminated with antibiotic resistant bacteria. This study allows concluding that appropriate use of antibiotics in compliance with good hygiene practices is essential to reduce the antibiotic resistance identified in this preliminary study

Modelling of parasitic effects induced by electrically active defects in a SiGe HBT

In this paper, we present a numerical modelling of a NPN SiGe heterojunction bipolar transistor (HBT) realized in an industrial 0.35 µm BiCMOS process, using our own software simulator “SIBIDIF”, taking into account some electrically active defects in the HBT device. The electric performances of this device can be penalized by the presence of defects inherent to the complex structure shrinking. For our devices, most of these relevant defects are located at the vertical interface between the spacers and the polysilicon emitter, due to the Reactive Ion Etching (RIE) process step. Nevertheless, their localization, as well as theirs effective density or their capture section, have an influence on the electric characteristics of the HBT's. As a check, we find some good agreement between our simulated results and some experimental ones. Our work is focused on the identification of defects responsible for the current fluctuations at the origin of low frequency noise or Random Telegraphic Signals in industrial submicronic BiCMOS technologies. Gummel characteristics are simulated in order to identify generation-recombination or trap assisted tunnelling process in the base current. We have shown that devices having an excess base current present random discrete fluctuations on the base current

Аналіз самонагрівання SiGe HBT, призначеного для ВЧ-застосувань, за процентним вмістом германію

Основною метою роботи є визначення впливу процентного вмісту германію в основі SiGe біполярного транзистора з гетеропереходом (HBT) для аналіза ефекта самонагрівання пристрою. Ми використовуємо комерційне програмне забезпечення COMSOL Multiphysics. Модель пов'язує напівпровідниковий модуль з модулем HTS (Heat Transfer in Solids). Це дозволяє моделювати розподіл температури на пристрої SiGe HBT для рівнів германію в межах від x = 10 %, 20 % до x = 30 %. Спочатку ми визначаємо статичний коефіцієнт підсилення (β) SiGe HBT шляхом варіювання процентного вмісту германію. Крім того, ми аналізуємо розподіл тепла на поверхні компонента для трьох розглянутих рівнів германію, щоб визначити максимальну температуру Tmax в пристрої. Дійсно, для x = 10 % максимальна температура становить Tmax = 377 K і близька до переходу база-колектор. При збільшенні фракції германію в сплаві SiGe (x = 20 %) максимальна температура самонагрівання зменшується (Tmax = 366 K), тоді як при x = 30 % температура самонагрівання зменшується ще більше Tmax = 354 K), і вона поширюється на весь компонент. Це явище серйозно погіршує електричні характеристики HBT.The main purpose of this paper is to determine the impact of germanium percentage within the base of a SiGe heterojunction bipolar transistor (HBT) in order to analyze the effect of the device self-heating. We use the COMSOL Multiphysics commercial software. The model links the semiconductor module to the HTS (Heat Transfer in Solids) module. This allows to simulate the temperature distribution across the SiGe HBT device for germanium levels ranging from x = 10 %, 20 % to x = 30 %. We first determine the static gain (β) of the SiGe HBT by varying the percentages of germanium. In addition, we analyze the heat distribution on the component surface for the three considered levels of germanium in order to record the maximum temperature Tmax in the device. Indeed, for x = 10 %, the maximum temperature is Tmax = 377 K and is close to the base-collector junction. When the germanium fraction in the SiGe alloy is increased (x = 20 %), the maximum temperature of self-heating decreases (Tmax = 366 K), while for x = 30 % the temperature of self-heating decreases more (Tmax = 354 K) and it spreads over the entire component. This phenomenon degrades seriously the electrical performances of the HBT

Feeding practices of dairy cows in Algeria: Characterization, typology, and impact on milk production and fertility

Objective: To explore feeding strategies and identify eventual errors that could cause poor pro-duction and reproduction performances in dairy farms in the north of Algeria.Materials and Methods: A survey was conducted among 211 farms of different sizes, from 2014 to 2018 to compose a database that is analyzed statistically.Results: The results relative to the nutritive value of the rations showed an average dry matter intake of 15.9 ± 4.74 kg/cow/day, providing 13.2 ± 4.34 UFL (Feed Unit for Lactation) of net energy and 1306 ± 456 gm of protein digested in small intestine (PDI)/cow/day. A high proportion of concentrate intake is observed, with an average of 64.7% ± 17.4% of energy intake and 70.2% ± 16.2% of nitrogen intake.Dairy cows performances were characterized by a low milk productionregarding their genetic potential (14.2 ± 4.73 kg of milk/cow/day), a calving interval > to one year (397 ± 20.4 days), though the coverage rates of their nutrient requirements reached 120%.The typology of the dietary rations allowed grouping them into three categories: deficient rations cluster (DR), correct rations cluster, and excessive rations cluster (ER). DR and ER, which are not adjusted to animals’ needs, were found in 57.8% of farms.Conclusion: It is obvious that the feeding management in the dairy farms in the North of Algeria is not based upon scientific achievements, contributing to relatively low performances of cows as well as to important financial losses. This finding imposes the necessity to adopt a correct and accurate rationing of animals

Вплив ізоляції канавок на явище самонагрівання у вдосконаленому радіочастотному біполярному транзисторі з гетеропереходом SiGe

Робота спрямована на визначення впливу ізоляції канавок на самонагрівання та електричні характеристики біполярного транзистора з гетеропереходом (HBT) SiGe, розглянута структура відповідає 0,25 мкм технології BiCMOS7G. Вдосконалення технології SiGe досягається в основному зменшенням розмірів пристрою та розробкою його архітектури для поліпшення радіочастотної ємності. Цікавою розробкою є впровадження ізоляції мілких та глибоких канавок. Вона дозволяє значно зменшити паразитні ємності та забезпечити плоску топографію після епітаксії основи SiGe. Недоліком такого впровадження є підвищення температури в пристрої через явище самонагрівання. Це відповідає внутрішньому тепловиділенню на транзисторних переходах. Для оптимізації цього ефекту ми розглянемо модель неізотермічного енергетичного балансу (NEB), засновану на методі кінцевих елементів та двовимірному тепловому моделюванні. Ця модель враховує, зокрема, температуру носіїв та надлишкові ефекти, що виникають у діапазоні розмірів розглянутих пристроїв. Потім проводиться аналіз впливу ізоляції канавок (мілких та глибоких) на електричні характеристики радіочастотного HBT SiGe з урахуванням теплового переносу носіїв. Для реалізації електротермічного моделювання використовували програмне забезпечення SILVACO-TCAD, яке поєднує модуль Athena (технологічний процес) та модуль Atlas. Ми змоделювали статичний коефіцієнт підсилення, динамічні характеристики (fT, fmax) та проаналізували розподіл тепла з ізоляцією канавок та без неї. Показано, що в сучасних структурах HBT SiGe з ізоляцією канавок та при режимах високої потужності температура решітки може значно перевищувати 300 К, і тому електричні характеристики β, fT, fmax значно погіршуються. Отримані результати узгоджуються з деякими опублікованими експериментальними даними.This work aims to determine the effect of the trench isolation on the self-heating and electrical performances of SiGe heterojunction bipolar transistor (HBT), the considered structure corresponds to BiCMOS7G 0.25 µm technology. Advanced SiGe technologies are essentially achieved with downscaling of the device dimensions and developing its architecture to improve the radio frequency capacity of the device. An interesting development is the introduction of the Shallow and Deep Trench isolation (STI, DTI). These make it possible to reduce considerably the parasitic capacitances and to provide a flat topography after SiGe base epitaxy. The drawback of this is the temperature rise in the device through the self-heating phenomenon. This corresponds to the internal heat dissipation at the transistor junctions. To optimize this effect, we consider the non-isothermal energy balance (NEB) model based on the finite element method and two-dimensional thermal simulations. This model takes into account, particularly, the temperature of the carriers and the overshoot effects which occur in the range of dimensions of the considered devices. Analysis of the effect of trench isolation (shallow and deep trench isolation) on electrical performances of radio frequency SiGe HBT is then carried out considering thermal transfer of the carriers. The software SILVACO-TCAD coupling Athena module (technological process) and Atlas module were used to achieve electro-thermal modeling. We simulated the static gain, the dynamic characteristics (fT, fmax) and analyzed the heat distribution with and without trench isolation. It is shown that in these modern SiGe HBT structures with trench isolation and for high power regimes, the lattice temperature can greatly exceed 300 K and so the electrical performances β, fT, fmax are significantly degraded. The obtained results agree with some published experimental data

TCAD simulation of small-pitch 3D sensors for pixel detector upgrades at High Luminosity LHC

Applications at the High Luminosity LHC (HL-LHC) have required the development of a new generation of 3D pixel sensors with increased pixel granularity, extreme radiation hardness and low material budget. To this purpose, new 3D pixels have small pitch (e.g., 50×50 or 25×100 μm2) and reduced active thickness (∼100 μm). Owing to the small inter-electrode spacing (∼28 μm in the most aggressive designs). These 3D pixels are expected to be radiation hard even after irradiation at the hadron fluences. Indeed, they are of interest for the innermost tracking layers of ATLAS and CMS (∼2×1016 neq cm−2), and beyond. In order to estimate the charge collection efficiency (CCE) after irradiation, TCAD simulations can be conveniently used, providing useful information for the optimization of sensor design and fabrication technology. Within the AIDA-2020 project, with reference to the new single-sided 3D technology from FBK (Trento, Italy), we have simulated the CCE of pixel sensors with different inter-electrode spacing irradiated at different fluences. For these simulations, a 2D domain was used, consisting of a horizontal slice taken at half the depth of a 3D sensor. Simulations consider the hit of a minimum ionizing particle, described by the Heavy Ion model at different points within the active area. In addition, bulk radiation damage is accounted by using advanced deep-level trap models. This paper reports a comprehensive description of the simulation results based on a radiation model validated by comparison to experimental results from n-in-p strip detectors at 248 K and 900 V bias