Článek podává přehled o roli vokalické kvantity a jejích vazbách s dalšími aspekty jazykového systému ve 12 jazycích. Na základě popisu těchto jazyků je vypracována elementární typologie: 1) slovanské jazyky (mimo ruštinu), latina a spisovná arabština (fo-nologická role, téměř žádná korelace s kvalitou samohlásek, s přízvukem a s typem slabiky); 2) germánské jazyky a částečně ruština (sekundární fonologická role, korelace s kvalitou samohlásek a s přízvukem); 3) románské jazyky (absence fonologické role, absence korelace s kvalitou samohlásek, korelace s přízvukem a s typem slabiky).
The influence of air humidity on leaf-air gas exchange and leaf water potential (4^) was investigated during daily courses in control and water stressed potted young plants of Copaifera langsdorffii. When leaf-air water vapour concentration difference (AW) increased during the day, stomatal conductance (g^) and net photosynthetic rate (P]vj) decreased under both soil moistures. Moderate AW induced lower values of g^ and Pn unwatered than control plants, High AW in atmosphere produced strong depression in g^ (from 0.22 to 0,01 mol m'^ s’’) and (from 6.5 to 0.7 pmol m'2 s'*) in control plants around midday, with recuperation of T'. Expected conductance tese) was calculated as fimction of AW, which was useful for discriminating soil to atmosphere water stress. In špite of momentary T or soil water stress, P^, g^, and water use efficiency decreased when AW increased during day course.
During health surveys of 7- to 9-week-old goldfish (Carassius auratus L.) fingerlings in a fish farm near Budapest, Hungary, myxosporean plasmodia were observed on the fins. Plasmodia were most frequently found at the intersegmental joints of the finrays. Spores of Myxobolus diversus Nie et Li, 1973 known from China, were detectable in the mature plasmodia located within the lumen, and less often on the surface, of the cartilaginous finrays. The external wall of the plasmodia was constituted by a capsule formed from a collagenous material identical with the cartilaginous substance of the finrays. Matured plasmodia were filled by spores of 12-14 × 8-9.5 µm in size. The relatively small plasmodia caused only small deformities on the fins. Their importance is, however, not negligible, as in an ornamental fish such as the goldfish even a minor damage of the fins causes a loss of value. Besides a report on the first European occurrence and pathological aspects, a redescription of this parasite of Far-Eastern origin is given.
Nudaciraxine imperium sp. n. (Monogenea: Axinidae) is described from the gills of the needlefish Tylosurus acus imperialis (Rafinesque) caught in the Gulf of Gabès, Tunisia. This new species mainly differs from both previously described species, Nudaciraxine gracilis (Linton, 1940) Price, 1962 from Strongylura marina (Walbaum) and Nudaciraxine cabosanlucensis Payne, 1990 from Ablennes sp., by having more testes (42 vs. 20-22 and 32, respectively). Nudaciraxine imperium also differs from N. gracilis by having a median vaginal pore (submedian in N. gracilis), narrower clamps (52-70 µm vs. 75-100 µm) and differently shaped haptoral lateral hamuli. From N. cabosanlucensis it can be distinguished by a J-shaped rather than U-shaped ovary, a longer cirrus pouch (125-190 µm vs. 64-70 µm), an oesophageal bifurcation slightly anterior to genital complex (immediately after pharynx in N. cabosanlucensis) and a wider guard on the lateral hamuli. In agreement with Payne (1990), the diagnosis of the genus Nudaciraxine Price, 1962 is amended as follows: vaginal pore dorsal, median to submedian, armed or not with horn-like spines. This is the first report of the genus Nudaciraxine in the Mediterranean Sea. The potential use of axinid monogeneans as biological tags for subspecies of belonid fishes is discussed.
Ectoparasitic Prototransversotrema steeri Angel infected Acanthopagrus australis (Günther) in western (W. Bay) and southern (S. Bay) Moreton Bay with greatest abundance in winter (June - August), and none in summer (December - February). This confirms previous observations on seasonality of P. steeri from a small estuary in New South Wales. Transversotrema licinum Manter, which is a new host and geographical record, infects A. australis in W. Bay but not S. Bay, with large abundances in summer and winter, lowest abundance in spring. Increased size of P. steeri in winter in S. Bay could be explained by increased size offish sampled since fish length and size of each parasite species were correlated positively. Transversotrema licinum increased in size from summer to winter irrespective of fish size. Number of eggs in utero and parasite size were correlated for both species; worms in mid-size range had most eggs, and P. steeri had more eggs (average = 19.2, 0-80) than T. licinum (3.3, 0-21); eggs were similar in length. Number of eggs per parasite, adjusted for parasite size, was greatest in autumn (P. steeri) or summer (T. licinum), i.e. early in infection period. Spawning migration to eastern Moreton Bay did not influence number of eggs per parasite.
Four grapevine cultivars, i.e. Cabernet Sauvignon (a member of the Western Europe cultivar group), Rizamat (a member of the East cultivar group), Red Double Taste (a hybridized cultivar from Vitis vinifera L. and V. labrusca L.), and 1103Paulsen (a hybridized rootstock), were treated by three severity orders of drought stress for 25 d. Then net photosynthetic rate (PN), maximal photochemical efficiency (Fv/Fm), actual photochemical efficiency (ΦPS2) of photosystem 2, total electron transport rate (JT), and electron transport flows used in carboxylation (JC) and in oxygenation (JO) reactions catalysed by ribulose-1,5-bisphosphate carboxylase/oxygenase were determined. PN was determined again after re-watering for 2 d by gas exchange measurement. Along with the increase in severity of drought stress, PN, Fv/Fm, ΦPS2, JT, and JC in all four cultivars decreased. The range of decrease differed among cultivars. JO expressed various trends from cultivar to cultivar. In Rizamat that received slight and moderate drought stress, PN evidently decreased, but JO markedly increased, thus maintaining high values of JT and ΦPS2. Prior to the moderate drought stress, the Fv/Fm was high in Rizamat, indicating that the photodamage had not happened ahead of the moderate drought stress given. Under the severe drought stress, the photorespiration rate in Rizamat decreased by 70 %, and JT, ΦPS2, and Fv/Fm also dropped to very low values, i.e. the photodamage of photosynthetic apparatus has taken place. This suggested that the photorespiration has consumed the excessive assimilatory power and the photo-protective function of photorespiration is very important for Rizamat. When Cabernet Sauvignon grew under drought stress, its JO decreased in a small range, thus maintaining higher values of JC, JT, ΦPS2, and Fv/Fm; hence no serious photodamage occurred. Despite of the fact that PN of cv. Red Double Taste decreased markedly under the slight drought stress, JO still increased under the severe drought stress. This suggests that photorespiration is important in photoprotection under drought stress. JO in cv. 1103Paulsen markedly decreased under slight stress. Accordingly, PN, Fv/Fm, ΦPS2, JT, and JC decreased to extremely low values. Thus photorespiration effectively protects the photosynthetic apparatus from photo-damage under drought, assists in maintaining a relatively high ΦPS2, and helps PN to be rapidly recovered after re-watering. and X. Q. Guan ... [et al.].
The present article shows formulations and interpretations of the basic mathematical relations that contain Fermi characteristic quantities and relate to the electron conductance of a homogeneous metallic or semiconducting thin layer. Two approaches to this conductance are chosen, namely from the standpoint of wave number or energetic quantum states of conductive electrons in dependence on their concentration, absolute temperature and acted homogeneous electrostatic field. The theoretical analyses are carried out for drifted and diffused conductive electrons. The relations formulated are of practical importance for development of modern integrated electronical and opto-electronical devices. and Prezentovaný článek uvádí formulace a interpretace základních matematických relací, obsahujících Fermiho charakteristické veličiny a vztažených k elektronové vodivosti homogenní kovové nebo polovodičové tenké vrstvy. Je zvolen dvojí přístup k této vodivosti, a to z hlediska vlnočtových nebo energetických kvantových stavů vodivostních elektronů v závislosti na jejich koncentraci, absolutní teplotě a působícím homogenním elektrostatickém poli. Teoretické analýzy jsou provedeny pro driftové a difuzní vodivostní elektrony. Formulované relace mají praktický význam pro rozvoj moderních integrovaných elektronických a optoelektronických zařízení.