bluuebunny/crossref_metadata_2025 huggingface dataset:
Children presenting with end‐stage renal disease of unexplained etiology: Implications for disease recurrence after transplantation
Authors: Butani Lavjay
Published: May 2006

Abstract:  With longer graft and patient survival, recurrent disease is becoming recognized as an increasingly important contributor to long‐term graft loss in renal transplant recipients. However, patients may present for the first time in end‐stage renal disease (ESRD) leading to uncertainty as to their underlying diagnosis and the risk of recurrence. The purpose of this study was to describe the features of children who presented for the first time in ESRD and to determine the predictive value of investigations in differentiating diseases with and without a recurrence risk. From 7/99 to 11/04, 13 children presented to our center in ESRD. Their median age was 13.3 yr; 77% were male. The majority were hypertensive (77%) and oligoanuric (69%). All had proteinuria (median urine protein to creatinine ratio [Up/c] 7.0), and 92% had microhematuria. Only seven had small kidneys on ultrasound. All children underwent a serologic work‐up and six (46%) were biopsied. Of the 13 children, seven had a glomerular disease; in five the diagnosis was made on biopsy, in one on serologic testing and one by family history. Of the remaining six children, three had non‐glomerular diseases: obstructive uropathy in one and primary hyperoxaluria type 1 in two, and 3 had an unknown disease. When patients with glomerular diseases were compared with those with non‐glomerular diseases, the two predictors for glomerular disease were a lower serum albumin (p = 0.004) and a higher serum bicarbonate level (p = 0.01). Comparing patients with and without a risk of recurrence, there were no differences between the two groups in any of their demographic, clinical, or biochemical parameters by analysis of variance (including serum albumin or proteinuria). In summary, the vast majority of children presenting in ESRD have hematuria and proteinuria, even with non‐glomerular diseases. The significant overlap in clinical features between patients with and without a risk of recurrence emphasizes the need for all children presenting in ESRD to be evaluated extensively so that disease recurrence after transplantation can be anticipated or even prevented.
Effect of bile duct obstruction on the expression of intestinal mRNA related to cholesterol and bile acid metabolism in the rat
Authors: Kamisako Toshinori , Ogawa Hiroshi
Published: May 2006

Background and Aim:  The liver and small intestine play an important role in maintaining cholesterol and bile acid balance within the body. The purpose of this study was to evaluate the effect of bile duct ligation (BDL) on the expression of intestinal and hepatic genes that are important for cholesterol and bile acid metabolism.

Methods:  Rats were allocated to the BDL group or the sham operation group. Blood, liver and small intestine were obtained after 24, 72 and 168 h from both groups. Serum and hepatic lipids were measured by colorimetric assays and hepatic and intestinal mRNA related to lipid metabolism was studied by reverse transcription–polymerase chain reaction (RT‐PCR).

Results:  Hepatic apolipoprotein (Apo) AIV, multidrug resistant protein (Mrp)2, adenosine triphosphate (ATP) binding cassette transporter (Abc)g5 and Abcg8 expression constantly decreased after BDL. Intestinal Apo AIV, Apo CIII, Mrp2, Abcg5 and Abcg8 expression remarkably decreased 24 h after BDL and recovered 72 and 168 h after BDL. Hepatic small heterodimer partner (Shp) expression did not change after BDL. Conversely, intestinal Shp expression remarkably decreased 24 h after BDL (16% of sham operation) and slightly recovered 168 h after BDL (58% of sham operation).

Conclusion:  Several intestinal mRNA expressions important for lipid (Apo AIV, Apo CIII, Abcg5 and Abcg8) and bile acid (Mrp2 and Shp) metabolism were decreased in the early phase of obstructive jaundice and the expression of these intestinal mRNA recovered in the late phase of obstructive jaundice.
Long‐term trends and geographic variations in the survival of patients with hepatocellular carcinoma: Analysis of 11 312 patients in Taiwan
Authors: Chen Chien‐Hung , Su Wei‐Wen , Yang Sheng‐Shun , Chang Ting‐Tsung , Cheng Ken‐Sheng , Lin Hans Hsienhong , Wu Shun‐Sheng , Lee Chuan‐Mo , Changchien Chi‐Sin , Chen Chien‐Jen , Sheu Jin‐Chuan , Chen Ding‐Shinn , Lu Sheng‐Nan
Published: May 2006

Background/Aims:  The survival rates of patients with hepatocellular carcinoma (HCC) were investigated over the past 20 years to clarify the long‐term survival trend.

Methods:  A total of 11 312 patients with HCC from seven medical centers from 1986 to 2002 were included. Survival was analyzed by correlating data with the national mortality databank.

Results:  Multivariate analysis showed that the following factors were associated with shorter survival: male sex, younger age, hepatitis B virus, earlier year of diagnosis, alpha fetoprotein higher than 400 ng/mL, alanine aminotransferase (ALT) higher than two times the upper normal limit, higher aspartate aminotransferase (AST)/ALT ratio, central or southern Taiwan residence, and rural areas residence. Patients diagnosed during 1998–2002 showed the highest survival rate, followed by patients diagnosed during 1994–1997, 1990–1993, and 1986–1989, respectively.

Conclusions:  There are geographic variations in the survival rates of patients with HCC. Survival has been improving gradually over the past 20 years, probably due to earlier detection of HCC or to improved patient care.
Genetic and epigenetic alterations of the KLF6 gene in hepatocellular carcinoma
Authors: Song Jaehwi , Kim Chang Jae , Cho Yong Gu , Kim Su Young , Nam Suk Woo , Lee Sug Hyung , Yoo Nam Jin , Lee Jung Young , Park Won Sang
Published: May 2006

Background and Aim:  Kruppel‐like factor 6 (KLF6) is a zinc finger tumor suppressor gene that is frequently mutated in several human cancers and is broadly involved in differentiation and development, growth‐related signal transduction, cell proliferation, apoptosis, and angiogenesis. The aim of this study was to elucidate the potential etiological role of KLF6 in the development of hepatocellular carcinoma (HCC) in Korea.

Methods:  The gene mutation, allelic loss, and methylation status of the KLF6 gene was analyzed in a series of 85 Korean patients: 21 with dysplastic nodules and 85 with HCC.

Results:  No somatic mutations were observed in the patients with dysplastic nodules or with HCC. Allelic loss was found in five (6.8%) of 73 informative HCC tissues. Three of the five patients with allelic loss had HCC with hepatitis B virus infection and cirrhosis, and the remaining two had no viral infection and a non‐specific background. In methylation analysis, unmethylated and methylated DNAs of the KLF6 gene were amplified in all corresponding non‐neoplastic liver tissues. Only one HCC tissue showed methylated DNA without unmethylated DNA.

Conclusions:  The results suggest that genetic and epigenetic alteration of KLF6 may play a minor role in the development of HCC.
Fred Hollows Lecture: Hypertensive retinopathy – a journey from fundoscopy to digital imaging
Authors: Wong Tien Y
Published: May 2006

Abstract

Hypertensive retinopathy refers to a spectrum of retinal microvascular signs that develop in response to elevated blood pressure. These signs are broadly divided into localized signs (focal retinal arteriolar narrowing, arteriovenous nicking, retinal haemorrhages, cotton wool spots, hard exudates and microaneurysms) and diffuse signs (generalized retinal arteriolar narrowing, arterial wall opacification and optic disc oedema). Although their association with systemic morbidity was recognized more than a century ago, the prognostic significance of hypertensive retinopathy has not received much attention. In large part, this is because clinical assessment of hypertensive retinopathy signs with the direct fundoscopy has proven imprecise. Data from large population‐based studies in the past decade, using retinal photographic methods to define hypertensive retinopathy signs, have provided new insights into the epidemiology, systemic associations and clinical significance of hypertensive retinopathy. These studies show that hypertensive retinopathy signs are common (up to 14% of adults aged 40 years and older, even in those without clinical diabetes or hypertension) and are strongly associated with blood pressure. Various retinopathy signs predict the risk of stroke, congestive heart failure and cardiovascular mortality, independent of blood pressure and other risk factors. These data suggest that patients with hypertensive retinopathy signs may benefit from a careful cardiovascular evaluation, and appropriate risk reduction therapy if indicated. Future advances in digital retinal imaging technology will allow researchers and clinicians to better chart and monitor the vascular effects of hypertension.
Objective Testing Procedures in Linear Models: Calibration of thep‐values
Authors: JAVIER GIRÓN F. , LINA MARTÍNEZ M. , MORENO ELÍAS , TORRES FRANCISCO
Published: May 2006

Abstract. An optimal Bayesian decision procedure for testing hypothesis in normal linear models based on intrinsic model posterior probabilities is considered. It is proven that these posterior probabilities are simple functions of the classicalF‐statistic, thus the evaluation of the procedure can be carried out analytically through the frequentist analysis of the posterior probability of the null. An asymptotic analysis proves that, under mild conditions on the design matrix, the procedure is consistent. For any testing hypothesis it is also seen that there is a one‐to‐one mapping – which we callcalibration curve– between the posterior probability of the null hypothesis and the classicalbip‐value. This curve adds substantial knowledge about the possible discrepancies between the Bayesian and thep‐value measures of evidence for testing hypothesis. It permits a better understanding of the serious difficulties that are encountered in linear models for interpreting thep‐values. A specific illustration of the variable selection problem is given.
Moving Images: The Mobility and Immobility of ‘Kids Standing Still'
Authors: Neyland Daniel
Published: May 2006

Mobility is a frequently recurring theme in recent debates around the emergence of new technologies. However, with this increasing attention paid to mobility, how does ‘immobility’ become notable as an absence of mobility? How are such perceptions of immobility used to occasion assessments of motive, intent and moral standing? This paper features a sociological interrogation of examples of immobility made notable through expectations of mobility. It utilises a study of CCTV as its principle example of the constitution and assessment of mobility and immobility. The paper explores theoretical strategies available for interrogating these issues. It concludes through an engagement with the boundaries constituted around mobility and immobility. The ways in which forms of assessment operate through, and further maintain, these boundaries are considered.
Why do Underwriters Charge Low Underwriting Fees for Initial Public Offerings in Taiwan?
Authors: Chen Hsuan‐Chi , Fok Robert C. W. , Wang Yu‐Jen
Published: May 2006

Abstract:  In Taiwan, underwriting fees for initial public offerings (IPOs) are extremely low compared to fees in other countries. From 1989 to 1999, the average underwriting fee for IPOs in Taiwan is 0.99%—far below the regulatory limit. Although the Taiwanese underwriting industry is highly concentrated, underwriting fees do not cluster at any particular level. We examine the underwriting fee and income structure in Taiwan and find support for an incentive hypothesis. Underwriters have an incentive to charge lower underwriting fees when market demand for IPO shares increases and capital gains account for a larger portion of their total income.
Social‐cognition and the broad autism phenotype: identifying genetically meaningful phenotypes
Authors: Losh Molly , Piven Joseph
Published: May 2006

Background:  Strong evidence from twin and family studies suggests that the genetic liability to autism may be expressed through personality and language characteristics qualitatively similar, but more subtly expressed than those defining the full syndrome. This study examined behavioral features of this ‘broad autism phenotype’ (BAP) in relation to performance on a measure of social‐cognition in an attempt to tease out this complex clinical picture and identify markers of underlying neuropsychological systems of genetic significance to autism. We hypothesized that mild social‐cognitive impairment would be associated with clinically defined social characteristics of the BAP (aloof personality style, lower quality social relationships, and impaired pragmatic language use).

Method:  Forty‐eight parents of individuals with autism (13 of whom were identified as ‘aloof’), and 22 control parents, were administered the ‘Eyes Test’, a social‐cognitive measure that taps the ability to read complex psychological states from viewing only the eye region of faces.

Results:  Whereas social‐cognitive ability was unimpaired among parents of autistic children in general, the subgroup of parents defined as ‘aloof’ displayed significant social‐cognitive deficits on the ‘Eyes Test’. Impaired social‐cognitive ability was associated with low quality of friendships and problems with pragmatic language use, associations which mirror those documented in autism. Conclusions: Findings suggest that social‐cognitive impairments co‐segregate with conceptually related personality, social, and language features that constitute the BAP, and point towards performance on the Eyes Test as a genetically meaningful endophenotype.
WATER‐SOLUBLE CARBOHYDRATES OF SEEDS OF THE GRAMINEAE
Authors: MacLEOD Anna M. , McCorquodale H.
Published: May 2006

summary

Qualitative and quantitative determinations have been made of the sugars, oligosaccha‐rides and water‐soluble polysaccharides of the seeds of twenty‐two species of the Gramineae.

Although in most species sucrose was the most plentiful free sugar, in Lolium perenne and in Festuca pratensis a trisaccharide which contained residues of galactose, glucose and fructose and which was chromatographically distinct from raffinose constituted the most abundant oligosaccharide; in Elymus arenarius and in Bromus sterilis an homologous series of low‐molecular fructosans represented the major simple carbohydrate. Similar fructosans were also present in Agropyron repens.

Raffinose was present in fifteen of the seeds examined and stachyose in ten of these fifteen raffinose‐containing seeds. The contents of raffinose and stachyose were positively correlated.

Water‐soluble polysaccharides were obtained in yields approaching 1 per cent of the dry weight of the seeds from certain members of the Bromeae, the Hordeeae, the Festuceae and the Aveneae; yields from members of other tribes were low and predominantly dextrinous in nature.

A pure β‐glucosan, resembling that of cultivated barley, has been obtained from Bromus, from Avena and Arrhenatherum, and from Dactylis and other members of the Festuceae. The polysaccharide prepared from Nardus contained a high proportion of mannan and that from Molinia a high proportion of galactan.

When the water‐soluble carbohydrates of these seeds are considered in relation to the classification of the Gramineae, it is seen that Bromus is quite distinct from Brachy‐podium; that the members of the Festuceae here examined show underlying similarity in the composition of their water‐soluble polysaccharides, though Festuca pratensis and Lolium perenne are distinctive in containing an unusual trisaccharide; that Avena and Arrhenatherum differ from the other two members of the Aveneae examined (Holcus and Anthoxanthum) and that the members of the Hordeae constitute a natural group on the basis of their sugars content.
ASEXUAL SPORES IN CLOSTERIUM DIDTMOTOCUM RALFS
Authors: STARR RICHARD C.
Published: May 2006

summary

Closterium didymotocum var. pygmaeiim is described as a new variety because of its narrow width and its lack of subapical thickenings on the cell wall. An unusual type of asexual spore formation is described in which the protoplast escapes from the enclosing cell wall and forms a spherical resistant spore. On germination the spore produces a single vegetative cell.
CYTOGENETIC STUDIES IN TUBEROUS SOLANUM SPECIES
Authors: MARKS G. E.
Published: May 2006

Summary

Meiosis was studied in S. × vallis‐mexici (2n =36). Chromosome pairing tends towards the production of 12 bivalents and 12 univalents per cell. This indicates that the chromosome complement of S. ×vallis‐mexici consists of two similar genomes and one dissimilar genome which in turn suggests that this species is a hybrid between a diploid and an unrelated tetraploid species.

Bukasov (1939) and Hawkes (1956) suggest from morphological and geographical evidence that S. × vallis‐mexici is a natural hybrid between S. verrucosum (2n = 24) and S. stoloniferum (2n = 28). Thirty‐four triploid (2n = 36) hybrids, one aneuploid (2n = 37) hybrid and one tetraploid (2n = 48) hybrid were produced by crossing plants from two families of S. verrucosum with four different varieties of S. stoloniferum, C.P.C. 9.1, 9.2, 1331 and 2282.3.

The leaflet index and corolla shape were scored in each plant. Meiosis was also studied in detail. Those hybrids resulting from the use of C.P.C. 1331 and to a lesser degree those obtained using C.P.C. 9.1 and 9.2 are morphologically and cytologically similar to S. × vallis‐mexici. Hybrids produced using C.P.C. 2282.3 have leaflet indices similar to it, and corollas shaped like those of S. verrucosum.

These differences between the synthesized hybrids can also be expected to occur in natural hybrids. It is suggested, therefore, that the name S. × vallis‐mexici should be applied to all forms of hybrids between S. verrucosum and S. stoloniferum irrespective of whether or not they conform to the type.
THE EFFECTS OF SHORT PERIODS OF WATER STRESS ON THE GROWTH OF SUGAR BEET IN POTS
Authors: OWEN P. C.
Published: May 2006

Summary

Sugar beet, broad beans and lettuce growing in soil in pots were subjected to repeated short periods of water stress up to a maximum PF of 4.0. In some experiments the leaf areas of such plants were lower than those of plants grown under conditions of minimum water stress, but there was no significant effect of water stress on dry matter production or Net Assimilation Rate. The loss of water per unit leaf area was not affected by the water regime, but the cumulative water loss from pot and plant over the experiments was greater under the wet regime, partly because the leaf area was greater. In pot culture experiments, where the total amount of water within the root zone is relatively small, it is impossible to impose stress conditions above wilting point for long enough to produce detectable effects on growth. The results of water stress experiments may depend as much on the duration and timing of the periods of stress as on the level of stress imposed.
THE RELATION OF LEAF WATER DEFICIT TO SOIL MOISTURE TENSION IN PINUS SYLVESTRIS L.
Authors: SANDS K. , RUTTER A. J.
Published: May 2006

Summary

Experiments were carried out in which pots with 3–5 year old plants of Pinus sylvestris were allowed to dry from field capacity to soil water tensions of 5 atm. or more, while measurements of soil moisture tension, leaf water deficit and transpiration rate were made daily at sunrise and noon.

By fitting multiple regressions it was shown that most of the variation in the leaf water deficit could be accounted for by changes in soil moisture tension and transpiration rate.

The conclusion reached in earlier work was confirmed by these experiments, namely that the leaf water deficit at sunrise is the best index of the soil moisture conditions experienced by the plant, since effects of transpiration are negligible at this time. The effect of various factors on the relation between soil moisture tension and leaf water deficit was experimentally examined. It was found that the relation was affected by the age of needles used for the determination, by the time of year, by nitrogen nutrition, and by soil moisture conditions prior to the experimental run. The way in which these factors may operate is discussed.

Despite the variability in the relation examined, broad conclusions as to the soil moisture tension experienced by young plants of this species may be drawn from measurements of leaf water deficit made on 1‐year old leaves at sunrise. Thus in soils near field capacity, leaf water deficits rarely exceed 8 per cent. Deficits of 12–14 per cent indicate soil moisture tensions in the 1–5 atm. range, and when the deficits rise above 17 per cent, the soil moisture has probably been reduced to the permanent wilting percentage.
THE EFFECT OF PRE‐EMERGENT TREATMENT OF PEAS WITH TRICHLORACETIC ACID ON THE SUB‐MICROSCOPIC STRUCTURE OF THE LEAF SURFACE
Authors: JUNIPER BARRIE E.
Published: May 2006

Summary

Peas were sown in sand, which was treated with varying concentrations of trichloracetic acid. The behaviour of water droplets on the leaves of peas was observed, and it was found that the angle made by the droplet on the surface falls with increasing concentration of T.C.A. No changes in leaf structure, which could account for these changes in behaviour, were revealed by ordinary light microscopy. Investigation of the sub‐microscopic anatomy of the surface by the carbon replica technique under the electron microscope did reveal significant differences in the leaf surfaces. A reduction in the number and a change in form of the minute wax structures occurs with an increased concentration of T.C.A. in the soil. These changes correlate well with an increase in the wettability of the leaf surface as determined by the contact angle of water droplets.
THE ASCORBIC ACID SYSTEM IN PLANT TISSUES
Authors: BARKER J. , MAPSON L. W.
Published: May 2006

Summary

Evidence is presented which shows that when plant tissues are extracted with metaphosphoric acid at room temperature, some oxidation of ascorbic acid to dehydroascorbic acid occurs.

This oxidation was diminished, though no conclusive proof was obtained that it was eliminated, by extracting the tissue with either metaphosphoric acid at —3°C or with methanol‐metaphosphoric acid at —70°C, in the absence of oxygen.

An effect attributed to disorganization occurred if the tissue was held in the frozen state and as a result ascorbic acid Avas oxidized during disintegration in an acid extractant. The effect of disorganization was greater when the period in the frozen state was extended.

The lowest values for dehydroascorbic acid in plant tissues have been obtained, either by extraction in metaphosphoric acid at —3°C or by rapid freezing and immediate extraction with methanol‐metaphosphoric acid solution at —70°C, both extractions being carried out in the absence of oxygen. These procedures gave similar results within the limits of experimental error.
THE DORSIVENTRALITY OF LEAF PRIMORDIA
Authors: SNOW MARY , SNOW R.
Published: May 2006

summary

When in shoot apices of potatoes the presumptive area of I1, the next leaf due to arise, or of 12, was isolated from the growing‐point by a vertical cut, the isolated pieces regularly formed dorsiventral leaves, even when slips of mica were left in the cuts.

These results differ from those of Sussex, who reported that he obtained radial leaves from nearly similar operations on potatoes, and interpreted them as due to interruption of an induction of dorsiventrality by the apex.

The difference in the results cannot be explained by supposing that our isolated pieces were larger than his, since the evidence indicates that they were smaller. It may have been due to differences in the conditions of culture.

In apices of Epilobium hirsutum on the other hand, I1 areas when isolated by vertical cuts developed often into radial leaves, though sometimes into dorsiventral leaves. So also did P, primordia if isolated on small pieces at early plastochron.

These and other experiments on E. hirsutum make it probable that in that species the dorsiventrality of the leaves is induced by the apex. But this cannot be concluded with certainty, since the experiments show also that reduction of size contributes towards making an isolated I1 or P1 develop as a radial leaf, and it remains possible that this factor may have been effective alone.

In earlier experiments on E. hirsutum P1, I, or I2 was narrowly confined between two vertical radial cuts, without being isolated from the apex, and several of these confined primordia or presumptive areas formed radial leaves, which are illustrated. But in more numerous later experiments this result was not obtained again.

The determination of the dorsiventrality of leaves in these and other species is briefly discussed.
THE MODE OF ORIGIN OF VEIN‐ENDINGS IN THE LEAF OF LIRIODENDRON TULIPIFERA L.
Authors: SLADE BRENDA F.
Published: May 2006

Summary

In a study of the development of the reticulate venation of the leaf of Liriodendron tulipifera L. the mode of origin of the vein‐endings receives particular attention.

At an early stage in development the veins form a network with very few free ends. Increase in area of the lamina by cell enlargement is accompanied by expansion of the vein system. Its weaker components which are not capable of extending at the same rate as the lamina become broken or disconnected and produce the abundant blindly ending veinlets characteristic of the mature leaf. The pattern of development thus agrees with that already described for Cercis and Primus and probably occurs generally in dicotyledon leaves with reticulate venation.
CYTOGHROME OXIDASE IN MYCORRHIZAL AND UNINFEGTED ROOTS OF FAGUS SYLVATICA
Authors: HARLEY J. L. , PREES T. A.
Published: May 2006

Summary

The effect of azide, cyanide, carbon monoxide and DNP upon the respiration of mycor‐rhizal roots of beech is stimulatory. The stimulations are shown to be the result of the reaction of the fungal sheath. Host tissue of mycorrhizas and of uninfected roots react in a more expected fashion and are inhibited by azide, cyanide and carbon monoxide. In spite of this the fungal sheath is shown to possess a succinic dehydrogenase‐cytochrome oxidase system inhibited by malonate, cyanide and azide. Host tissue, whether from infected or uninfected roots, gives extracts containing a heat‐stable reductant of cytochrome C which interferes with spectrophotometric assay of the oxidase system. It is concluded that a significant part of electron transport of intact mycorrhizas may pass through the cytochrome oxidase system and, on inhibitor evidence alone, that the respiration of the host tissues is catalysed also by such a system. An explanation of stimulatory effects of inhibitors of cytochrome oxidase is suggested and discussed.
PHYSIOLOGICAL AND ECOLOGICAL FACTORS INFLUENCING THE EFFECTS OF MYCORRHIZAL INOCULATION
Authors: LEVISOHN I.
Published: May 2006

Summary

Inoculations of mycelia known to be mycorrhiza‐formers of certain tree species have frequently been recorded to produce indifferent effects on the development of these species. In a particular heathland soil, the introduction of Boletus scaber was even observed to depress the vigour of birch, a tree which is generally regarded as the mycor‐rhizal host parexcellence of this fungus. Pot‐culture experiments revealed that the harmful influence of the inoculum on the higher plant was due to certain fungal interactions. From an analysis of the fungal components concerned in these interactions, it appeared that the interplay of two factors was mainly responsible for bringing about the adverse effect on the young trees: (a) the physiological character of the particular form of B. scaber used as inoculum, i.e. its pronounced rhizosphere activity; (b) the presence of a deleterious pseudomycorrhiza‐former, Mycelium radicis atrovirensβ, in the experimental soil. Introduction of Boletus scaber into cultures of Pinus sylvestris demonstrated that, although this tree species is, generally, not a congenial mycorrhizal partner of the fungus, the formation of mycorrhizal infection and simultaneous growth stimulation of the host plant was achieved under certain ecological conditions.
THE MORPHOLOGY AND CYTOLOGY OF SPOROGENESIS OF TRICHOMANES PROLIFERUM BL.
Authors: BELL P. R.
Published: May 2006

Summary

The morphology of Trichomanes proliferum is described and the anatomy of the petiole and rhizome is discussed in relation to the habitat of the plant and its growth.

It is suggested that after the initial phases each frond may be regarded as a more or less independent colony of cells, the complexity ultimately attained by the frond depending upon the supply of primary metabolites reaching it directly from without.

It is reported that in the plant collected from Gunong Poe the chromosomes failed to pair at meiosis and 108 univalents were present.

A means is suggested by which polyploidy could have arisen frequently in the Hymenophyllaceae.
THE CYTOLOGY OF THE DESMIDS: THE CHROMOSOMES*
Authors: KING G. C.
Published: May 2006

Summary

New cytological techniques for handling desmid chromosomes are described. Twenty new chromosome counts are recorded.

Parallel disjunction of chromatids at anaphase has been observed for the first time in the desmids, and from this and other criteria it has been inferred that a non‐localized type of centromeric organization of the chromosomes is present.
AMINO ACID CONTENTS OF SOME MARINE ALGAE FROM BOMBAY
Authors: LEWIS E. J. , GONZALVES ELLA A.
Published: May 2006

Summary

Twelve species of algae from Bombay were analysed by quantitative paper chromatographic technique. The methods of preparation of protein‐hydrolysates, the resolving solvent system, Colour reagents and a modified colorimetric elution reagent have been described. In all, twenty amino acids were identified and estimated. From these ornithine is a rare record for marine algae, while hydroxyproline is a new record. The results obtained here compare favourably with those of other workers.
THE COMPARATIVE BIOLOGY OF CLOSELY RELATED SPECIES LIVING IN THE SAME AREA
Authors: MCNAUGHTON I. H. , HARPER JOHN L.
Published: May 2006

Summary

The morphology of Papaver dubium and P. lecoqii are contrasted. The colour of latex, leaf dissection, petal shape and height of stamens are considered good characters for distinguishing between them. The shape of the capsule and stigmatic disc are considered unreliable taxonomic characters.

Experimental cross‐pollinations show that the species can produce hybrids readily, that the hybrid seed germinates with little or no dormancy, to give plants showing some degree of hybrid vigour but morphological characters intermediate between the parents. The F1 hybrids show very severely reduced fertility, but this is rapidly restored in many of the F2 and backcross progeny.

Naturally occurring hybrids have not been found, and there are problems in the way of recognizing them and proving their hybrid nature if they do occur.

The continued coexistence of these two species without merging of their specific characters is made possible by barriers to gene flow occurring at three levels of organization: (a) ability of the parents to set seed by selfing, (b) ill‐adapted hybrids and (c) infertility of the F1 generation.
SHORT‐TERM FLUCTUATIONS IN LEAF AND INTER‐NODE GROWTH IN THE APPLE ROOTSTOGK CRAB C
Authors: HANCOCK C. R. , BARLOW H. W. B.
Published: May 2006

Summary

A method of handling data on leaf and internode growth on Crab C stoolbed shoots is described whereby average values for leaf length, leaf width and internode length were obtained from twenty‐seven shoots, with certainty that all leaves contributing to the average were passing through the same stage of development at the same time.

The effect of temperature (defined as accumulated day degrees above 42° F between noon and noon) on growth rate at five stages of growth of the leaf in length and width, and of the internode in length, is shown by means of linear regressions.

Attempts are made to relate final leaf length with the temperature regime through which the leaf had passed; partial correlations and a multiple regression gave results which are difficult to interpret.

Similar treatment of the internode data yielded a more logical relationship.

‘Normal curves of growth’ were constructed for leaf length, leaf width and internode length. By plotting these on a common time scale certain relationships between growth of one organ and another are clarified.

The effect of temperature at stages earlier than those observed in these studies is discussed.
CARROT TISSUE AND ETHANOL
Authors: LOWE CELIA , JAMES W. O.
Published: May 2006

Summary

The presence of alcohol in an aerated external medium increases the respiration rate of carrot discs. If the alcohol is labelled no labelling appears in the CO2 emitted or the acids formed in the tissue. Alcohol dehydrogenase is shown to be located almost wholly among the soluble proteins of the cytoplasm. The failure to oxidize alcohol is attributed to its spatial separation from the terminal oxidase system located in the mitochondria.
ROOT FORKING OF PINE SEEDLINGS GROWING UNDER NON‐STERILE CONDITIONS
Authors: LEVISOHN IDA
Published: May 2006

Summary

It has been demonstrated under particular pot‐culture conditions that, without establishing an association, the mycorrhiza‐formers Boletus bovinus, B. granulatus, Mycelium radicis nigrostrigosum, and Rhizopogon luteolus are capable of inducing short‐root forking in actively growing pine seedlings, while haustorial (pseudomycorrhizal) mycelium causes forking accompanied by infection. A number of soil fungi which are not common root associates failed to bring about dichotomous root branching, but there is evidence that certain other mycelia, whose identity is not known yet, can do so.

In water‐cultures of pines tryptophan induced root forking, the kind and degree of branching depending on the concentration of tryptophan.

From a morphological study of the root systems developing in pot‐ and in water‐cultures, it would appear that two types of forking may occur in both infected and uninfected pine roots, and that one type is connected with the activity of mycorrhiza‐formers, while the other seems to develop under the influence of non‐mycorrhizal fungi and can also be induced by certain growth‐substances and other media so far not defined.
POLLEN SPECTRA FROM RECENT HELIANTHEMUM COMMUNITIES
Authors: PROCTOR M. C. F. , LAMBERT CAMILLA A.
Published: May 2006

Summary

Pollen spectra are given from eight present‐day habitats of Helianthemum species. From a consideration of the recent and Late‐glacial spectra it is concluded that Helianthemum‐rich communities contributed only a part of the Late‐glacial pollen rain, and that they were probably mostly grass‐dominated. Some implications of the occurrence of Helianthemum for Late‐glacial conditions are discussed.
DIFFERENTIAL RESPONSE TO CALCIUM WITHIN THE SPECIES FESTUCA OVINA L.
Authors: SNAYDON R. W. , BRADSHAW A. D.
Published: May 2006

Summary

An investigation of population differentiation within the species Fcstuca ovina in relation to soil factors has shown that populations within this species differ greatly in their response to calcium in culture solution. Populations from acid, low calcium soils showed a weak response to calcium, whilst those from calcareous soils showed a strong response. All populations responded linearly to the logarithm of the calcium concentration at the low levels, but there was a decrease in yield of the acidic populations at higher calcium levels. The difference in response to calcium between the acidic and calcareous types of populations was as great as that previously shown to exist between extreme calcicole and calcifuges species. Such differences were found even between populations taken from areas only about I mile apart.

Smaller scale variation was also shown to exist between individuals within single populations.

Chemical analysis of the plants indicated that the differences in response between populations were due to differences in ability to absorb calcium from low solution concentrations, rather than to differences in ability to metabolize at low internal concentrations of calcium. The populations were also found to differ in ability to absorb other cations and in ability to root at low levels of calcium.

The evolutionary significance of the results is discussed, and the importance of recognizing such variability, within apparently homogeneous species, in ecological and physiological studies is stressed.
STUDIES IN BRITISH PRIMULAS
Authors: WOODELL S. R. J. , VALENTINE D. H.
Published: May 2006

Summary

Artificial autotetraploids of three species of Primula have been made and crossed reciprocally with their diploid parents.

Data on the character of the seeds produced, derived from dissection and embryo‐logical examination, are presented. It is shown that the seeds from reciprocal diploid‐autotetraploid crosses fall into two classes, type A and type B, which resemble in general features and pattern of development those from reciprocal crosses between the diploid species. They are normally practically empty at maturity, and no triploid offspring have been obtained.

Diploid‐autotetraploid crosses in general are discussed, and it is pointed out that the nature and goodness of their seeds varies greatly from genus to genus. The crosses can be arranged in four groups on a basis of triploid productivity.

The embryological data on these crosses are also briefly reviewed. While some general similarities can be recognized, there is so much diversity that no generalizations about the pattern of breakdown can be made.
COMPARATIVE CYTOLOGICAL STUDIES OF THE POLLEN AND POLLEN‐TUBES IN DIPLOID AND TETRAPLOID SPECIES OF SESBANIA
Authors: DANA S. K. , DATTA R. M.
Published: May 2006

Summary

Both Sesbania aculeata and S. speciosa have binucleate, prolate, tricolpate pollen grains.

The rate of pollen‐tube growth in vitro is higher in S. speciosa than in S. aculeata. The maximum pollen‐tube length for the former is 2151.5 μ and for the latter 1062.0 μ. The tubes continue to grow in culture for 8 hours.

The tube‐nucleus generally precedes the generative cell, but sometimes follows it.

The generative nucleus divides normally with regular equational division of its chromosomes.

Spindle formation is clear, and the spindle can develop in any position in relation to the longitudinal axis of the pollen‐tube.

Cytokinesis takes place by cell‐plate formation.

Two sperms are formed.

S. aculeata has twenty‐four chromosomes in somatic cells, and only one pair has secondary constrictions. Meiosis is regular, with rare multivalent formation. Although a polyploid race its behaviour is that of a diploid.

S. speciosa has twelve chromosomes in somatic cells, and only one pair has secondary constrictions.
FLOWERING BEHAVIOUR, COMPATIBILITY AND MAJOR GENE DIFFERENCES IN HOLCUS LANATUS L.
Authors: BEDDOWS A. R.
Published: May 2006

Summary

Holcus lanatus is wind‐pollinated. Anthesis occurs twice a day if weather conditions are favourable, the first time between 5 and 9 a.m. and the second between noon and 4 p.m. G.M.T. The two florets composing the spikelet each produce anthers but the upper may sometimes be hermaphrodite and can then develop a caryopsis.

Self‐compatibility varies from low to very low, and plants of high self‐fertility, not uncommon in other species, have not been found. The I1 progenies frequently contain mutant seedlings, and of these a lethal yellow and a lethal pale green are described. Neither type developed anthocyanin even when genes for its production were present. The possible reasons for this are discussed.

The great majority of uncultivated (wild) plants are anthocyanin‐positive. The purple colour is especially prominent along the veins of the sheaths and forms a diagnostic character. Failure to produce anthocyanin is a result of homozygosity for recessive allelomorphs at either of two loci. The non‐anthocyanin plants occasionally found fall, therefore, into two groups which can be genetically designated CCrr and ccRR.

A number of other qualitative differences were studied, including a new mutant dark green dwarf. This has very short broad leaves and crowded tillers, resulting in a rosette‐like plant about 6 cm in diameter. In all instances the differences were controlled by a single gene.

Although H. lanatus shows much variability in the degree of hairiness, a truly glabrous plant has not yet been found.
DAY‐LENGTH AS RELATED TO VEGETATIVE DEVELOPMENT IN ULEXEUROPAEUS I.
Authors: MILLENER L. H.
Published: May 2006

Summary

Seedling development, especially in respect of the ‘juvenile‐adult’transition, is shown to be far‐reachingly affected by day‐length. Extension of high‐intensity, short‐day illumination with sub‐compensation‐point light affects leaf and branch ontogeny both qualitatively and quantitatively. It is suggested that the changes affecting vegetative growth that go on during the low‐intensity light phase are of a formative nature, and that they may be more fundamental, in a general metabolic sense, than photoperiodic reactions (flower‐inducing) sensu stricto.
THE FINE STRUCTURE OF THE POLLEN WALL OF TILIA PLATYPHTLLOS
Authors: CHAMBERS T. C. , GODWIN H.
Published: May 2006

Summary

Thin sections of the pollen wall of Tilia platyphyllos and T. europaea have been studied by electron microscopy and it has proved possible to obtain both serial transverse sections and surface sections. An attempt has been made to relate the electron micrographs to the structures seen under the light microscope. It appears that an inner and an outer layer of the exine are joined by a system of hollow funnels and pillars crossing a cavity or void occupied by cytoplasm. In terms of density to an electron beam no support can be found for the idea that the exine is made up of layers of inherently different properties, nor for the present complex nomenclature applied to light microscope interpretations of pollen‐wall structure. Tapetal cytoplasm has been found to be continuous with cytoplasm in the wall of the pollen grain, and spheroids comparable with those described by Rowley et al. (1959) have been found associated with the tapetal strands surrounding the developing microspores.
RATES OF MITOSIS IN A PARTIALLY SYNCHRONOUS MERISTEM
Authors: CLOWES F. A. L.
Published: May 2006

Summary

In root apices of Sinapis alba mitosis is partially synchronous under certain cultural conditions, with two maxima and two minima of mitotic index each day. But the phase of the partial synchrony is different in the stele and cortex from that in the cap initials and that in the quiescent centre. The average rates of mitosis vary from once in 35 hours in the cap initials to once in 500 hours in the quiescent centre. Cells of the cortex and stele divide more slowly near the quiescent centre than at 150 microns from it. In this respect Sinapis differs from Zea and the dissimilarity in organization may be due to the possession of partial synchrony and the opportunity it gives for phasic differences in synthesis.
DAY‐LENGTH AS RELATED TO VEGETATIVE DEVELOPMENT IN ULEX EUROPAEUS L.
Authors: MILLENER L. H.
Published: May 2006

Summary

The extent of the juvenile phase in gorse seedlings grown under uniform conditions from seed collected from various stations throughout Britain, has been shown to vary significantly with the latitude of the parent plants. Regular seasonal variation in the juvenile‐adult balance of seedlings has also been demonstrated. Day‐length seems to be the only environmental factor which can be postulated to explain such variations—for it alone changes consistently with latitude and from season to season.
THE EFFECTS OF INJECTING 2,3,5,‐TRIIODOBENZOIC ACID INTO KALAMCHOE DAIGREMONTIANA*
Authors: BOHLEN JOSEPH , APPLEGATE HOWARD G.
Published: May 2006

Summary

Low concentrations of 2,3,5‐triiodobenzoic acid (TIBA) injected into Kalanchoe daigremontiana induced hyponasty while high concentrations induced epinasty. Changes in oxygen uptake preceded any visible morphological changes. Both hyponasty and oxygen uptake varied directly with the concentration of TIBA. Following injection very little lateral movement of TIBA occurred. Virtually all the TIBA initially moved directly up or down from the point of injection. This movement could be correlated with the vascular anatomy of K. daigremontiana. Explanations are advanced to account for the hyponasty, epinasty and oxygen uptake induced by TIBA.
THE UPTAKE AND ASSIMILATION OF AMMONIA BY NEOCOSMOSPORA VASINFECTA
Authors: BUDD K. , HARLEY J. L.
Published: May 2006

Summary

A low‐nitrogen mycelium prepared by suspending freshly grown mycelium in a nitrogen‐free medium for 22 to 24 hours was transferred to buffered media containing NH4Cl as sole nitrogen source for estimation of ammonia absorption. In one experiment a 'sugar‐starved’mycelium, obtained by suspending the fresh mycelium for a similar period in a medium lacking both nitrogen and glucose, was employed.

During the absorption of ammonia by low‐nitrogen mycelium, there is an increase in the ammonia content of the cells, and also in the total organic nitrogen, showing that assimilation of ammonia takes place. The rate of increase of both forms of nitrogen is greatest during the first 10 minutes of uptake and the maximum level of ammonia in the cells is reached within this initial period. External glucose is required for maximal uptake only after the second hour and it increases only the rate of assimilation. In the sugar‐starved mycelium, uptake of ammonia is considerably smaller: ammonia increases within the cells but ammonia assimilation is very slow in the absence of external glucose.

The chief soluble product of ammonia assimilation is glutamine. Ethanol‐insoluble nitrogen compounds are also formed, suggesting that proteins may be synthesized.

Assimilation of ammonia is only slightly affected by external ammonia concentration above 5 mM, but is markedly sensitive to temperature, external pH, anaerobic conditions and low concentrations of sodium azide or 2,4–dinitrophenol. The effects of the last three factors indicate that ammonia assimilation depends upon aerobic respiration, including the transfer of high‐energy phosphate. The level of ammonia in the mycelium depends on the external concentration and pH; it is reduced by anaerobic conditions and by sodium azide and 2,4–dinitrophenol although sensitivity to these factors is apparently much smaller than is that of ammonia assimilation. The participation of respiration is therefore implicated both in the assimilation of ammonia and also in some process leading to the increase of ammonia in the mycelium.
ANEUPLOIDY IN YEAST
Authors: COX B. S. , BEVAN E. A.
Published: May 2006

Summary

Heterozygous white diploid strains of yeast of which one parent is a particular red adenine‐requiring haploid strain often throw a large number of red sectors when they are plated on nutrient agar. It has been shown by genetic analysis and other tests that many of the white spore cultures from one such heterozygote are disomic haploids of constitution n+1 =AD1/ad1. By an extension of the analysis to the red spore cultures from the same heterozygote, it has been shown that some of these are also disomic haploids of constitution n+1 =ad1/ad1. It is concluded that the red haploid strain involved in the heterozygote is a trisomic haploid of constitution n+2 =ad1/ad1/ad1. The genetical significance of the diploid → aneuploid → diploid cycle in a fast multiplying unicellular organism is discussed.