Linear, diatomic crystal: single-electron states and large-radius excitons

The large-radius exciton spectrum in a linear crystal with two atoms in the unit cell was obtained using the single-electron eigenfunctions and the band structure, which were found by the zero-range potential (ZRP) method. The ground-state exciton binding energies for the crystal in vacuum appeared to be larger than the corresponding energy gaps for any set of the crystal parameters.Comment: 9 pages, 1 figure, 1 tabl

Сучасні напрямки створення та удосконалення пробіотиків

The article describes the topical areas of improvement of probiotics, such as: study of the physiology of promising industrial strains in order to select nutrient media for their cultivation;  determination of sorption processes of probiotic bacteria as a general biological process; study of the role of metabolic products and biologically active substances of microbial cells to define the nature of the adhesins and the mechanism of antagonistic activity; development of technology for the manufacture of complex products based on consortia of bacteria with a wide spectrum of antagonistic activity; research and synergistic inhibitory effects of various species and strains of probiotic bacteria; improved methods of control of antagonistic activity of preparations containing viable microbial cells and the development of methods for the determination of living organisms and the development of drugs for the correction of the intestinal microflora is not only, but also other open cavities of the human body.Статья посвящена актуальным направлениям усовершенствования пробиотиков, таким как: исследование физиологии перспективных производственных штаммов бактерий с целью подбора питательных сред для их культивирования; определение процессов сорбции пробиотических бактерий как общебиологического процесса; изучение роли продуктов метаболизма и БАВ микробной клетки для определения природы адгезинов и механизма антагонистической активности;  разработка технологий изготовления комплексных препаратов на основе консорциумов бактерий с широким спектром антагонистической активности; исследование синергического и ингибиторного действия разных видов и штаммов пробиотических бактерий; усовершенствование методов контроля антагонистической активности препаратов,  которые содержат жизнеспособные  микробные клетки и разработка методов их определения; создание препаратов для коррекции микрофлоры не только кишечника, но и других открытых полостей организма человека. Стаття присвячена актуальним напрямкам удосконалення пробіотиків, таким як: дослідження фізіології перспективних виробничих штамів з метою підбору поживних середовищ для їх культивування; визначення процесів сорбції пробіотичних бактерій як загальнобіологічного процесу; вивчення ролі продуктів метаболізму та біологічно активних речовин мікробної клітини для визначення природи адгезинів і механізму антагоністичної активності;  розробка технології виготовлення комплексних препаратів на основі консорціумів бактерій з широким спектром антагоністичної активності; дослідження синергічної та інгібіторної дії різних видів та штамів пробіотичних бактерій; вдосконалення методів контролю антагоністичної активності препаратів, що містять життєздатні мікробні клітини та розробка методів визначення вмісту живих мікроорганізмів; розробка препаратів для корекції мікрофлори не лише кишечнику, а й інших відкритих порожнин організму людини.

One-electron states and interband optical absorption in single-wall carbon nanotubes

Explicit expressions for the wave functions and dispersion equation for the band p - electrons in single-wall carbon nanotubes are obtained within the method of zero-range potentials. They are then used to investigate the absorption spectrum of polarized light caused by direct interband transitions in isolated nanotubes. It is shown that, at least, under the above approximations, the circular dichroism is absent in chiral nanotubes for the light wave propagating along the tube axis. The results obtained are compared with those calculated in a similar way for a graphite plane.Comment: 16 pages, 8 figures, 1 tabl

Spatially and polarization resolved plasmon mediated transmission through continuous metal films

The experimental demonstration and characterization is made of the plasmon-mediated resonant transmission through an embedded undulated continuous thin metal film under normal incidence. 1D undulations are shown to enable a spatially resolved polarisation filtering whereas 2D undulations lead to spatially resolved, polarization independent transmission. Whereas the needed submicron microstructure lends itself in principle to CD-like low-cost mass replication by means of injection moulding and embossing, the present paper demonstrates the expected transmission effects on experimental models based on metal-coated photoresist gratings. The spectral and angular dependence in the neighbourhood of resonance are investigated and the question of the excess losses exhibited by surface plasmons is discusse

Ефективність дорощування гібридних поросят з різною масою при постановці за рідкої системи їх годівлі

The intensity of growth of piglets, their preservation during rearing, and the payment of feed by the increments of animals that were placed for rearing with a design live weight of 7 kg and 20 % less than the design weight – 5.5 kg were studied. Also, the ratio of consumption of compound feed of different recipes during rearing, their cost, and the efficiency of rearing piglets at different staged live weights were studied. It was established that piglets that weighed 1.58 kg less at the beginning of rearing, when placed on rearing during this period, showed 20.9 % lower growth energy, due to which they had 19.6 % lower absolute growth during this period, which caused together with a lower production weight, a 20.3 % lower weight when transferred to fattening and an 8.8 % worse feed payment in increments, they consumed 31.4 % more of the expensive first pre-starter feed during the growing period, and 11.9 % less than the second cheaper pre-starter compound feed and 42.6 % less than the cheapest starter compound feed, as a result of which the cost of feed consumed by the animals of the experimental group was 10.6 % lower compared to the analogs of the experimental group. But taking into account the significantly lower absolute growth of the animals of the experimental group, the cost of feed for 1 kg of growth was 11.2 % higher in comparison with the similar indicator of animals that were put on growing at a designed live weight of 7.0 kg. At the same time, rearing piglets under the conditions of putting them into this process with the design live weight contributed to a decrease of 11.2 % in the cost of feed per kilogram of growth, an increase of 20.3 % in the cost of one piglet after the completion of rearing, and a 23.1 % increase in the income from its sale and 1.07 % higher profitability of raising one head, but resulted in 10.6 % higher feed and operating cost of rearing 1 head and 19.6 % higher operating cost of one piglet at the end of rearing.Вивчались інтенсивність росту поросят, їх збереженість під час дорощування та оплата корму приростами тварин, які були поставлені на дорощування за проектної живої маси 7 кг та на 20 % меншою від проектної – 5,5 кг. Також вивчалось співідношення споживання комбікормів різних рецептур під час дорощування, їхня вартість та ефективність дорощування поросят за різної постановочної живої маси. Встановленно, що поросята, які мали на початок дорощування меншу на 1,58 кг вагу, при постановці на дорощування під час цього періоду виявили на 20,9 % нижчу енергію росту, за рахунок чого мали менші на 19,6 % абсолютні прирости за цей період, що спричинило разом з меншою постановочною масою на 20,3 % нижчу масу при переведенні на відгодівлю та гіршу на 8,8 % оплату корму приростами, вони спожили за час дорощування на 31,4 % більше дорогого першого престартерного корму, та на 11,9% менше дешевшого другого престартерного комбікорму і на 42,6% менше найбільш де шевшого стартерного комбікорму, в результаті чого вартість спожитих кормів тваринами дослідної групи виявилось на 10,6 % меншою порівняно з аналогами дослідної групи. Але враховуючи суттєво нижчий абсолютний приріст у тварин дослідної групи, кормова собівартість 1 кг приросту у них виявилась на 11,2 % вищою порівняно з аналогічним показником тварин, яких ставили на дорощування за проектної живої маси 7,0 кг. Водночас дорощування порсят за умов постановки їх на цей процес з проектною живою масою посприяло зменшенню на 11,2 % кормової собівартості одного кілограма приросту, підвищенню на 20,3 % вартості одного поросяти по завершенні дорощування та на 23,1 % доходу від його реалізації і на 1,07 % вищій рентабельності вирощування однієї голови, але спричинило вищу на 10,6 % кормову та операційну собівартість дорощування 1 голови та на 19,6 % операційну собівартість одного підсвинка на кінець дорощування

Effectiveness of different systems of liquid feeding of piglets for additional growing in the conditions of industrial technology

The article, a comparative analysis of the productivity of piglets during rearing under a liquid feeding system with fodder mixtures, which were mixed in the feed containers of the Hydro Mix Pro feeding system of the Big Dutchmen company and with the help of the portioned feeding system Spotmix II of the Austrian company Schauer, is made. It was found that the preparation and distribution of feed using the Spotmix II portioned feeding system resulted in 1.5 % better piglet survival, 9.6 % higher piglet growth rate during rearing, 9.5 % higher absolute gains during this period, higher by 7.3 % of the weight of animals when transferred to fattening compared to analogs that were raised on liquid feeding with feed mixing in feed tanks. It has been proven that piglets that were prepared, transported, and distributed feed using the Spotmix II system consumed 6.0 % more feed per day, consumed 7.0 % more during the period, the cost of which was 10.6 % higher. Meanwhile, their feed conversion was 2.3 % better, with almost the exact feed cost per kilogram gain. The feeding of piglets in growing-out using the Spotmix II portioned liquid feeding system led to a 10.6 % higher cost of feed, a 22.1 % higher amortization costs for the equipment for feed distribution and animal feeding, a 9.6 % higher cost of the growing-out process of one pig, and its cost price at the end of the growing period is 3.4 times higher. At the same time, such feeding contributed to higher growth energy of animals during rearing, which caused a 7.3 % higher sales price of piglets, a 17.3 % higher profit from the sale of one head, and a 5.2 % higher profitability of rearing piglets compared to liquid feeding using Hydro Mix Pro system with feed mixing in feed tanks

Measurement of Muon Capture on the Proton to 1% Precision and Determination of the Pseudoscalar Coupling g_P

The MuCap experiment at the Paul Scherrer Institute has measured the rate L_S of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in a time projection chamber filled with 10-bar, ultra-pure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. L_S is determined from the difference between the mu- disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2 10^10 mu- decays, from which we extract the capture rate L_S = (714.9 +- 5.4(stat) +- 5.1(syst)) s^-1 and derive the proton's pseudoscalar coupling g_P(q^2_0 = -0.88 m^2_mu) = 8.06 +- 0.55.Comment: Updated figure 1 and small changes in wording to match published versio

Measurement of the Rate of Muon Capture in Hydrogen Gas and Determination of the Proton's Pseudoscalar Coupling gPg_P

The rate of nuclear muon capture by the proton has been measured using a new experimental technique based on a time projection chamber operating in ultra-clean, deuterium-depleted hydrogen gas at 1 MPa pressure. The capture rate was obtained from the difference between the measured $\mu^-$ disappearance rate in hydrogen and the world average for the $\mu^+$ decay rate. The target's low gas density of 1% compared to liquid hydrogen is key to avoiding uncertainties that arise from the formation of muonic molecules. The capture rate from the hyperfine singlet ground state of the $\mu p$ atom is measured to be $\Lambda_S=725.0 \pm 17.4 s^{-1}$, from which the induced pseudoscalar coupling of the nucleon, $g_P(q^2=-0.88 m_\mu^2)=7.3 \pm 1.1$, is extracted. This result is consistent with theoretical predictions for $g_P$ that are based on the approximate chiral symmetry of QCD.Comment: submitted to Phys.Rev.Let

Isolation, crystallization, and investigation of ribosomal protein S8 complexed with specific fragments of rRNA of bacterial or archaeal origin. Biochemistry 66

Study of the nature of protein-rRNA complexes is a topical problem of modern molecular biology. Structural studies of rRNA-protein complexes are the most direct and precise method of analysis of these interactions. Because ribosomal proteins are most conservative during evolution, their complexes with specific RNA fragments provide an interesting model for studying RNA-protein interactions. Ribosomal protein S8 from E. coli plays a key role in assembling the small ribosomal subunit The major region of protein S8 binding on 16S rRNA was determined by partial hydrolysis with restric tion endonucleases The binding sites of protein S8 on 16S rRNA are similar in E. coli and T. thermophilus. It was shown that ACCELERATED PUBLICATION 0006 2979/01/6609 0948$25.00 ©2001 MAIK "Nauka / Interperiodica" * To whom correspondence should be addressed. Vol. 66, No. 9, 2001, pp. 948 953. Translated from Biokhimiya, Vol. 66, No. 9, 2001, pp. 1165 1171. Original Russian Text Copyright © 2001 Abstract-The core ribosomal protein S8 binds to the central domain of 16S rRNA independently of other ribosomal proteins and is required for assembling the 30S subunit. It has been shown with E. coli ribosomes that a short rRNA fragment restrict ed by nucleotides 588 602 and 636 651 is sufficient for strong and specific protein S8 binding. In this work, we studied the complexes formed by ribosomal protein S8 from Thermus thermophilus and Methanococcus jannaschii with short rRNA frag ments isolated from the same organisms. The dissociation constants of the complexes of protein S8 with rRNA fragments were determined. Based on the results of binding experiments, rRNA fragments of different length were designed and syn thesized in preparative amounts in vitro using T7 RNA polymerase. Stable S8-RNA complexes were crystallized. Crystals were obtained both for homologous bacterial and archaeal complexes and for hybrid complexes of archaeal protein with bac terial rRNA. Crystals of the complex of protein S8 from M. jannaschii with the 37 nucleotide rRNA fragment from the same organism suitable for X ray analysis were obtained