Jalkaväkimiinojen suorituskykyä korvaavat tykistöasejärjestelmät

Suomi liittyy henkilömiinat kieltävään Ottawan sopimukseen vuonna 2012 ja hävittää jalkaväkimiinat vuoden 2016 loppuun mennessä. Jalkaväkimiinojen suorituskyky on pääosin korvattavissa. Jalkaväkimiinojen suorituskyvyn korvaaminen on toteutettava useiden, teknisesti kehittyneiden, mutta kalliiden osajärjestelmien yhdistelmällä. Suomelle on ehdotettu hankittavaksi muun muassa, itsenäisiä sensorijärjestelmiä, älypanoksia, joissa on integroidut sensorijärjestelmät sekä tykistön tai heittimistön älyammuksia. Pääesikunnan maavoimaosaston mukaan hankittavilla korvaavilla järjestelmillä on kyettävä korvaamaan jalkaväkimiinojen suorituskyky seuraavissa tehtävissä - panssari- ja ajoneuvomiinojen sekä esteiden ja murrosteiden suojaaminen sekä niiden raivaamisen estäminen tai vaikeuttaminen (ajanvoiton hankkiminen) - omien joukkojen ryhmityksen suojaaminen - alueen vapaan käytön estäminen hyökkääjältä - tappioiden tuottaminen hyökkääjälle. Tutkimuksen pääkysymys on, miten tykistöasejärjestelmää voidaan käyttää miinoitteen tehon nostamiseen sekä miinoittamiseen ja mitkä ovat ne tykistöasejärjestelmän osat, joilla miinoitteen suorituskyky ylläpidetään tai kehitetään? Tutkimuksen pohjaksi lasketaan tavanomaisen sulutteen teho vihollisen mekanisoitua komppaniaa vastaan. Saatua tulosta verrataan tykistöasejärjestelmän tuottamiin tappioihin vastaavaa maalia vastaan sekä arvioidaan, minkälainen yhteisvaikutus järjestelmillä on. Tutkimuksessa selvitetään tykistöasejärjestelmän kyky valvontaan ja maalinosoitukseen, tulivaikutukseen erityisesti miinoitteisiin liittyen sekä kaukomiinoittamiseen. Kymmenien kilometrien etäisyydelle vaikuttamaan kykenevät asejärjestelmät vaativat tehokkaan maalinosoitusjärjestelmän tai niiden suurta kantamaa ei kyetä täysin hyödyntämään. Ranger – lentotiedustelujärjestelmä on tehokas väline maalien paikantamiseen vihollisen selustasta, sen käyttöä rajoittaa lähinnä lennokkien vähäinen määrä ja toimintakyky vaativissa sääolosuhteissa. Sulutteiden valvontaan tehokkaimpia laitteita ovat maastonvalvontatutkat sekä sensorivalvontajärjestelmät. Maastovalvontatutkien keskimääräinen havaintoetäisyys ihmiseen on 1000 – 5000 metriä, joka riittää esimerkiksi pataljoonan painopistesuunnan sulutteiden valvontaan. Tulevaisuudessa miinoitteiden valvontaan tarkoitetut sensorivalvontajärjestelmät tulevat todennäköisesti olemaan pääosin miinoitteisiin asennettavia, pienikokoisia valvontalaitteita, joiden toiminta perustuu esimerkiksi infrapuna-, seismisiin tai magneettisiin sensoreihin. Raskaasta raketinheittimestä tulee Suomessa merkittävä operatiivisen tulenkäytön väline hyvän kantaman ja erittäin suuren tulen tehon ansiosta. Kaukomiinoittamiseen kykenevät AT2 miinaraketit ovat tehokkaita ja tulevat laajentamaan tavanomaisen panssarimiinoittamisen keinovalikoimaa huomattavasti. Raskaan raketinheittimen käyttöä rajoittaa eniten ampumalaitteiden vähyys sekä alkuvaiheessa yksipuoleinen ampumatarvikevalikoima. Älykkäillä tytärammuksilla varustetuilla kuorma-ammuksilla kyetään vaikuttamaan tehokkaasti omaan miinoitteeseen pysähtynyttä panssaroitua vihollista vastaan laskematta merkittävästi oman miinoitteen torjunta-arvoa. Kuorma-ammuksilla saavutetaan maalialueella huomattavan korkea tulentiheys, joka aiheuttaa viholliselle tuntuvat tappiot. Tutkimuksessa todetaan, että jalkaväkimiinoitteiden suorituskyky voidaan pääosin korvata tykistöasejärjestelmällä. Suurimmat haasteet aiheutuvat valvontatarpeen laajuudesta. Valvottavia miinoitteita on paljon eikä kaikkialle ole mahdollista suunnata tykistön valvonta- ja maalinosoituslaitteita. Taistelujen painopisteeseen tykistöllä on kuitenkin tarjota erittäin moderneja ja tehokkaita valvonta- ja maalinosoitusjärjestelmiä, kuten maavalvontatutka ja Maakotka. Tulivoimassa jalkaväkimiinat kyetään korvaamaan, suoraan miinoitteeseen vaikuttamaan kykenevät DM 662 kuorma-ammukset aiheuttavat merkittävää tuhoa erityisesti jalkaväelle mutta myös panssaroitujen maalien tappioprosentti maalialueella on korkea. Kaukomiinoittamiskyvyllä nostetaan suluttamisjärjestelmän kyky alueen vapaan käytön estämiseen uudelle tasolle, etäisyys, työvoiman tarve ja aikatekijät muuttuvat merkittävästi miinarakettien myötä. Omien joukkojen ryhmityksen suojaamiseen erityisesti komppaniatasolla jalkaväkimiinat ovat erinomainen ase, jonka suorituskykyä on tykistöllä vaikea suoranaisesti korvata. Raketinheittimen miinaraketit kykenevät vastaamaan nopeasti yllättävään vihollisuhkaan sivusta suunnasta mutta niillä ei voi vaikuttaa riittävän lähelle omia joukkoja, jotta niiden suorituskyvyllä voitaisiin suoraan korvata jalkaväkimiinojen jättämä aukko katvealueiden ja vartiopaikkojen suojana.

Analyzing the efforts in furrow openers used in low power planters

The furrow openers for no-till system should be easy to penetrate the soil, generate low levels of soil mobilization and require a little traction force. Thus, the aim of this research was to compare six hoe-type furrow openers, four of industrial manufacturing and two handcrafted models, which were used in planters in the region of Pelotas, Brazil. The parameters for comparison among these furrow openers were the horizontal (Fh) and vertical (Fv) forces acting on the tip of the hoe and the cross-sectional area mobilized in the furrow. The experimental design was randomized, with six treatments (furrow openers) from T1 to T6, with four repetitions, constituted by their passage through plots of 20 x 3 m. The force data were collected by load cells and a signal conditioner. The determination of the mobilized area in the furrow was done by a micro soil profilometer. It was concluded that the furrow openers T1, T4 and T6 presented the lowest values of horizontal force (statistically equal and ranging between 1,034 and 1,230 N) and that T1 and T2 produced the highest vertical forces downwards (statistically identical and varying between 749 and 845 N). The furrow openers T1, T2, T4, T5 and T6 generated soil mobilization statistically equal and between 0.006993 and 0.008933 m².

Margaret Archerin dualistinen yhteiskuntateoria – kriittinen tarkastelu pragmatistisesta näkökulmasta

Margaret S. Archer (s. 1943) on tunnettu sosiologi ja yhteiskuntateoreetikko, niin kutsutun kriittisen realismin koulukunnan johtavia edustajia. Leimallisinta hänen teorialleen on erottaa ihmisten toiminta ja sosiaaliset rakenteet toisistaan ja mieltää ne dualistiseen tapaan kahdeksi emergentiksi todellisuuden tasoksi. Kummankin tason olioilla on omanlaisensa olemukset ja omia, mihinkään muuhun palautumattomia voimia, joiden ansiosta ne voivat olla aidoissa vuorovaikutuksissa muiden olioiden kanssa. Archerin mukaan tämä ontologinen oppi ja siihen tukeutuva analyyttinen dualismi on tärkeää yhteiskuntatieteiden metodologian kannalta, sillä toiminnan ja rakenteiden välistä vuorovaikutusta ei voida oikein ymmärtää, ellei niitä tällä tavoin eroteta toisistaan. Tässä tutkielmassa Archerin yhteiskuntateoriaa esitellään, eritellään ja arvioidaan kriittisesti pragmatistisesta, eritoten John Deweyn (1859– 1952) ajattelusta ammentavasta näkökulmasta, josta on luontevaa kyseenalaistaa monet perinteiset filosofiset dualismit. Samalla kun Archerin teoria paikannetaan yhteiskuntateorioiden kenttään, sen enemmän tai vähemmän julkilausutut käsitykset yhteiskunnasta ja kollektiiveista, ihmisyydestä, toimijuudesta, mielestä, kielestä ja sosiaalisista mekanismeista sekä niitä etsivistä tieteenaloista nostetaan tarkasteltaviksi. Archerin teorian vertailu monessa suhteessa erilaiseen pragmatistiseen lähestymistapaan, joka ei erota toimintaa ja rakenteita ontologisesti toisistaan vaan kannustaa ymmärtämään ne olennaisesti toisistaan riippuvaisiksi, valaisee Archerin teorian kriittisiä pisteitä ja paikoin kiistanalaisia oletuksia. Tutkielma paitsi selventää, myös haastaa ja koettelee Archerin teoriaa ja puntaroi parhaita argumentteja sen puolesta ja sitä vastaan.

Gastroduodenal resistance and neural mechanisms involved in saline flow decrease elicited by acute blood volume expansion in anesthetized rats

We have previously demonstrated that blood volume (BV) expansion decreases saline flow through the gastroduodenal (GD) segment in anesthetized rats (Xavier-Neto J, dos Santos AA & Rola FH (1990) Gut, 31: 1006-1010). The present study attempts to identify the site(s) of resistance and neural mechanisms involved in this phenomenon. Male Wistar rats (N = 97, 200-300 g) were surgically manipulated to create four gut circuits: GD, gastric, pyloric and duodenal. These circuits were perfused under barostatically controlled pressure (4 cmH2O). Steady-state changes in flow were taken to reflect modifications in circuit resistances during three periods of time: normovolemic control (20 min), expansion (10-15 min), and expanded (30 min). Perfusion flow rates did not change in normovolemic control animals over a period of 60 min. BV expansion (Ringer bicarbonate, 1 ml/min up to 5% body weight) significantly (P<0.05) reduced perfusion flow in the GD (10.3 ± 0.5 to 7.6 ± 0.6 ml/min), pyloric (9.0 ± 0.6 to 5.6 ± 1.2 ml/min) and duodenal (10.8 ± 0.4 to 9.0 ± 0.6 ml/min) circuits, but not in the gastric circuit (11.9 ± 0.4 to 10.4 ± 0.6 ml/min). Prazosin (1 mg/kg) and yohimbine (3 mg/kg) prevented the expansion effect on the duodenal but not on the pyloric circuit. Bilateral cervical vagotomy prevented the expansion effect on the pylorus during the expansion but not during the expanded period and had no effect on the duodenum. Atropine (0.5 mg/kg), hexamethonium (10 mg/kg) and propranolol (2 mg/kg) were ineffective on both circuits. These results indicate that 1) BV expansion increases the GD resistance to liquid flow, 2) pylorus and duodenum are important sites of resistance, and 3) yohimbine and prazosin prevented the increase in duodenal resistance and vagotomy prevented it partially in the pylorus

The Lebanese mutation as an important cause of familial hypercholesterolemia in Brazil

Familial hypercholesterolemia (FH) is a common autosomal disorder that affects about one in 500 individuals in most Western populations and is caused by a defect in the low-density-lipoprotein receptor (LDLr) gene. In this report we determined the molecular basis of FH in 59 patients from 31 unrelated Brazilian families. All patients were screened for the Lebanese mutation, gross abnormalities of the LDLr gene, and the point mutation in the codon 3500 of the apolipoprotein B-100 gene. None of the 59 patients presented the apoB-3500 mutation, suggesting that familial defective ApoB-100 (FDB) is not a major cause of inherited hypercholesterolemia in Brazil. A novel 4-kb deletion in the LDLr gene, spanning from intron 12 to intron 14, was characterized in one family. Both 5' and 3' breakpoint regions were located within Alu repetitive sequences, which are probably involved in the crossing over that generated this rearrangement. The Lebanese mutation was detected in 9 of the 31 families, always associated with Arab ancestry. Two different LDLr gene haplotypes were demonstrated in association with the Lebanese mutation. Our results suggest the importance of the Lebanese mutation as a cause of FH in Brazil and by analogy the same feature may be expected in other countries with a large Arab population, such as North American and Western European countries.

Autonomic abnormalities demonstrable in young normotensive subjects who are children of hypertensive parents

Although a slightly elevated office blood pressure (BP) has been reported in several studies, little is known about the prolonged resting blood pressure, heart rate (HR) and baroreflex sensitivity (BRS) of prehypertensive subjects with a family history of hypertension. Office blood pressure, prolonged resting (1 h) BP and HR were measured in 25 young normotensives with a positive family history of hypertension (FH+) and 25 young normotensives with a negative family history of hypertension (FH-), matched for age, sex, and body mass index. After BP and HR measurements, blood samples were collected for the determination of norepinephrine, plasma renin activity and aldosterone levels, and baroreflex sensitivity was then tested. Casual BP, prolonged resting BP and heart rate were significantly higher in the FH+ group (119.9 ± 11.7/78.5 ± 8.6 mmHg, 137.3 ± 12.3/74.4 ± 7.9 mmHg, 68.5 ± 8.4 bpm) compared to the FH- group (112.9 ± 11.4/71.2 ± 8.3 mmHg, 128.0 ± 11.8/66.5 ± 7.4 mmHg, 62.1 ± 6.0 bpm). Plasma norepinephrine level was significantly higher in the FH+ group (220.1 ± 104.5 pg/ml) than in the FH- group (169.1 ± 63.3 pg/ml). Baroreflex sensitivity to tachycardia (0.7 ± 0.3 vs 1.0 ± 0.5 bpm/mmHg) was depressed in the FH+ group (P<0.05). The FH+ group exhibited higher casual blood pressure, prolonged resting blood pressure, heart rate and plasma norepinephrine levels than the FH- group (P<0.05), suggesting an increased sympathetic tone in these subjects. The reflex tachycardia was depressed in the FH+ group.

Familial hyperaldosteronism

Aldosterone, the major circulating mineralocorticoid, participates in blood volume and serum potassium homeostasis. Primary aldosteronism is a disorder characterised by hypertension and hypokalaemia due to autonomous aldosterone secretion from the adrenocortical zona glomerulosa. Improved screening techniques, particularly application of the plasma aldosterone:plasma renin activity ratio, have led to a suggestion that primary aldosteronism may be more common than previously appreciated among adults with hypertension. Glucocorticoid-remediable aldosteronism (GRA) was the first described familial form of hyperaldosteronism. The disorder is characterised by aldosterone secretory function regulated chronically by ACTH. Hence, aldosterone hypersecretion can be suppressed, on a sustained basis, by exogenous glucocorticoids such as dexamethasone in physiologic range doses. This autosomal dominant disorder has been shown to be caused by a hybrid gene mutation formed by a crossover of genetic material between the ACTH-responsive regulatory portion of the 11ß-hydroxylase (CYP11B1) gene and the coding region of the aldosterone synthase (CYP11B2) gene. Familial hyperaldosteronism type II (FH-II), so named to distinguish the disorder from GRA or familial hyperaldosteronism type I (FH-I), is characterised by autosomal dominant inheritance of autonomous aldosterone hypersecretion which is not suppressible by dexamethasone. Linkage analysis in a single large kindred, and direct mutation screening, has shown that this disorder is unrelated to mutations in the genes for aldosterone synthase or the angiotensin II receptor. The precise genetic cause of FH-II remains to be elucidated.

Polymorphisms of the low-density lipoprotein receptor gene in Brazilian individuals with heterozygous familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a metabolic disorder inherited as an autosomal dominant trait characterized by an increased plasma low-density lipoprotein (LDL) level. The disease is caused by several different mutations in the LDL receptor gene. Although early identification of individuals carrying the defective gene could be useful in reducing the risk of atherosclerosis and myocardial infarction, the techniques available for determining the number of the functional LDL receptor molecules are difficult to carry out and expensive. Polymorphisms associated with this gene may be used for unequivocal diagnosis of FH in several populations. The aim of our study was to evaluate the genotype distribution and relative allele frequencies of three polymorphisms of the LDL receptor gene, HincII1773 (exon 12), AvaII (exon 13) and PvuII (intron 15), in 50 unrelated Brazilian individuals with a diagnosis of heterozygous FH and in 130 normolipidemic controls. Genomic DNA was extracted from blood leukocytes by a modified salting-out method. The polymorphisms were detected by PCR-RFLP. The FH subjects showed a higher frequency of A+A+ (AvaII), H+H+ (HincII1773) and P1P1 (PvuII) homozygous genotypes when compared to the control group (P<0.05). In addition, FH probands presented a high frequency of A+ (0.58), H+ (0.61) and P1 (0.78) alleles when compared to normolipidemic individuals (0.45, 0.45 and 0.64, respectively). The strong association observed between these alleles and FH suggests that AvaII, HincII1773 and PvuII polymorphisms could be useful to monitor the inheritance of FH in Brazilian families.

Insulin secretion, insulin sensitivity, and hepatic insulin extraction in first-degree relatives of type 2 diabetic patients

To identify early metabolic abnormalities in type 2 diabetes mellitus, we measured insulin secretion, sensitivity to insulin, and hepatic insulin extraction in 48 healthy normal glucose-tolerant Brazilians, first-degree relatives of type 2 diabetic patients (FH+). Each individual was matched for sex, age, weight, and body fat distribution with a person without history of type 2 diabetes (FH-). Both groups were submitted to a hyperglycemic clamp procedure (180 mg/dl). Insulin release was evaluated in its two phases. The first was calculated as the sum of plasma insulin at 2.5, 5.0, 7.5, and 10.0 min after the beginning of glucose infusion, and the second as the mean plasma insulin level in the third hour of the clamp procedure. Insulin sensitivity index (ISI) was the mean glucose infusion rate in the third hour of the clamp experiment divided by the mean plasma insulin concentration during the same period of time. Hepatic insulin extraction was determined under fasting conditions and in the third hour of the clamp procedure as the ratio between C-peptide and plasma insulin levels. FH+ individuals did not differ from FH- individuals in terms of the following parameters [median (range)]: a) first-phase insulin secretion, 174 (116-221) vs 207 (108-277) µU/ml, b) second-phase insulin secretion, 64 (41-86) vs 53 (37-83) µU/ml, and c) ISI, 14.8 (9.0-20.8) vs 16.8 (9.0-27.0) mg kg-1 min-1/µU ml-1. Hepatic insulin extraction in FH+ subjects was similar to that of FH- ones at basal conditions (median, 0.27 vs 0.27 ng/µU) and during glucose infusion (0.15 vs 0.15 ng/µU). Normal glucose-tolerant Brazilian FH+ individuals well-matched with FH- ones did not show defects of insulin secretion, insulin sensitivity, or hepatic insulin extraction as tested by hyperglycemic clamp procedures.

Archerin realismista pragmatismin rortylaiseen versioon

Kirjallisuusarvostelu

Metarefleksiiviset toimijat kaivavat maata modernin alta

Kirjallisuusarvostelu

Processamento térmico de purê de banana (Musa cavendishii, Lamb.) em embalagens flexíveis esterilizáveis

O objetivo deste trabalho foi estabelecer as condições de processo térmico de purê de banana, variedade "nanica", em bolsas esterilizáveis porção individual (130 x 170mm). Os frutos foram selecionados, aquecidos a 98°C/5min. para inativação enzimática, separadas as sementes e fibras num despolpador com malha de 0,08cm de diâmetro e depois o purê foi embalado nas bolsas sob um vácuo de 25mmHg, resultando em média 2,7ml de ar residual por bolsa. Em seguida as bolsas foram processadas sem agitação e em posição horizontal numa autoclave horizontal, a 115°C/158KPa, com imersão total de água quente. O tempo de manutenção do processo foi de 7,5min. Inicialmente foi utilizado o Clostridium butyricum como microrganismo alvo do processo, entretanto, observou-se que esta bactéria apresentara uma resistência térmica em purê de banana (pH 4,6) um pouco menor que o valor estimado para o Clostridium botulinum, D115=0,183min. e D115=0,236min respectivamente, sendo assim, o C. botulinum foi escolhido como microrganismo alvo da esterilização do produto. O valor de F121,1°C aplicado foi de 0,64min. para causar 12 reduções decimais, calculado segundo PFLUG (1985) para um pH de 4,6, e verificado pelo método geral. Este valor somente foi considerado para a fase de aquecimento, deixando a letalidade do resfriamento (0,34min.), que foi realizada com água à temperatura ambiente, como segurança de processo. Nos testes de penetração de calor foram encontrados os valores médio de fh=6,8min; jh=0,48; fc=17,4min. e jc=1,3 demonstrando assim, que o produto é altamente condutivo. Nenhuma alteração no produto nem nas embalagens foi notada após a aplicação do ensaio de esterilidade comercial em 36 bolsas processadas contendo purê de banana, confirmando assim, a eficácia do tratamento térmico aplicado.

Transferência de calor transiente na agitação linear intermitente de latas

Foi estudada a transferência de calor transiente na agitação linear e intermitente (ALI) de embalagens metálicas contendo simulantes de alimentos, objetivando-se sua aplicação em processos de pasteurização ou esterilização e conseqüentes tratamentos térmicos mais eficientes, homogêneos e com produto de melhor qualidade. Foram utilizados quatro meios fluidos simulantes de alimentos de diferentes viscosidades e massas específicas: três óleos e água. Foram combinados efeitos de cinco tratamentos, sendo: meio simulante (4 níveis), espaço livre (3 níveis), freqüência de agitação (4 níveis), amplitude de agitação (2 níveis) e posição das latas (4 níveis). Os ensaios de aquecimento e resfriamento foram feitos em tanque com água à temperatura de 98 °C e 17-20 °C, respectivamente. Com os dados de penetração de calor em cada experimento, foram calculados os parâmetros de penetração de calor fh, jh, fc e jc. Os resultados foram modelados utilizando-se grupos de números adimensionais e expressos em termos de Nusselt, Prandtl, Reynolds e funções trigonométricas (com medidas de amplitude e freqüência de agitação, espaço livre e dimensões da embalagem). Foram estabelecidas as duas Equações gerais para as fases de aquecimento e resfriamento: Nu = ReA –0,199.Pr –0,288.sen(xa/AM)0,406.cos(xf/FA)–1,039.cos((xf/FA).(EL/H).p)–4,556 Aquecimento Nu = 0,1295.ReA–0,047.Pr –0,193.sen(xa/AM)0,114.cos(xf/FA)–0,641.cos((xf/FA).(EL/H).p)–2,476 Resfriamento O processo de ALI pode ser aplicado em pasteurizadores ou autoclaves estáticas horizontais e verticais, com modificações simples. Concluiu-se que a ALI aumenta significativamente a taxa de transferência de calor, tanto no aquecimento como no resfriamento.

Atividade antioxidante de pimentas do gênero Capsicum

Foi avaliada a atividade antioxidante pelo Sistema β-caroteno/Ácido Linoleico, ensaio do radical DPPH• (2,2-difenil-1-picrilhidrazila), do extrato bruto (EB) e frações hexânica (FH), clorofórmica (FC) e acetato de etila (FA) das pimentas malagueta (C. frutescens), cambuci (C. baccatum var. pendulum), cumari (C. baccatum var praetermissum) e pimentão magali (C. annuum var. annuum). As concentrações de capsaicinoides e de fenólicos totais presentes nas pimentas também foram determinadas. Os resultados obtidos demonstraram que as FC e FA das pimentas apresentaram maior concentração de fenólicos totais e capsaicinoides, sendo que a pimenta cumari foi a espécie com maior concentração destes compostos. A melhor atividade antioxidante pelo Sistema β-caroteno/Ácido Linoleico, foi obtida para o EB e FA da pimenta cambuci, seguida do EB da pimenta malagueta. Pelo método DPPH a FC e FA apresentaram menores valores de EC50, sendo a pimenta cumari e cambuci as mais efetivas. Estes resultados demonstram que as pimentas cumari, cambuci e malagueta podem ser utilizadas como agentes antioxidantes naturais em alimentos.

Major general John Lejeune : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59974