3D strain map of axially loaded mouse tibia: a numerical analysis validated by experimental measurements

A combined experimental/numerical study was performed to calculate the 3D octahedral shear strain map in a mouse tibia loaded axially. This study is motivated by the fact that the bone remodelling analysis, in this in vivo mouse model should be performed at the zone of highest mechanical stimulus to maximise the measured effects. Accordingly, it is proposed that quantification of bone remodelling should be performed at the tibial crest and at the distal diaphysis. The numerical model could also be used to furnish a more subtle analysis as a precise correlation between local strain and local biological response can be obtained with the experimentally validated numerical model.     

γ-Tocopherol biokinetics and transformation in humans

Background: The uptake and biotransformation of γ-tocopherol (γ-T) in humans is largely unknown. Using a stable isotope method we investigated these aspects of γ-T biology in healthy volunteers and their response to γ-T supplementation.

Methods: A single bolus of 100 mg of deuterium labeled γ-T acetate (d²-γ-TAC, 94% isotopic purity) was administered with a standard meal to 21 healthy subjects. Blood and urine (first morning void) were collected at baseline and a range of time points between 6 and 240 h post-supplemetation. The concentrations of d² and d⁰-γ-T in plasma and its major metabolite 2,7,8-trimethyl-2-(b-carboxyethyl)-6-hydroxychroman (-γ-CEHC) in plasma and urine were measured by GC-MS. In two subjects, the total urine volume was collected for 72 h post-supplementation. The effects of γ-T supplementation on α-T concentrations in plasma and α-T and γ-T metabolite formation were also assessed by HPLC or GC-MS analysis.

Results: At baseline, mean plasma α-T concentration was approximately 15 times higher than γ-T (28.3 vs. 1.9 µmol/l). In contrast, plasma γ-CEHC concentration (0.191 µmol/l) was 12 fold greater than α-CEHC (0.016 µmol/l) while in urine it was 3.5 fold lower (0.82 and 2.87 µmol, respectively) suggesting that the clearance of α-CEHC from plasma was more than 40 times that of γ-CEHC. After d²-γ-TAC administration, the d² forms of γ-T and γ-CEHC in plasma and urine increased, but with marked inter-individual variability, while the d⁰ species were hardly affected. Mean total concentrations of γ-T and γ-CEHC in plasma and urine peaked, respectively, between 0–9, 6–12 and 9–24 h post-supplementation with increases over baseline levels of 6–14 fold. All these parameters returned to baseline by 72 h. Following challenge, the total urinary excretion of d²-γ-T equivalents was approximately 7 mg. Baseline levels of γ-T correlated positively with the post-supplementation rise of (d⁰ + d²) – γ – T and γ-CEHC levels in plasma, but correlated negatively with urinary levels of (d⁰ + d²)-γ-CEHC. Supplementation with 100 mg γ-TAC had minimal influence on plasma concentrations of α-T and α-T-related metabolite formation and excretion.

Conclusions: Ingestion of 100mg of γ-TAC transiently increases plasma concentrations of γ-T as it undergoes sustained catabolism to CEHC without markedly influencing the pre-existing plasma pool of γ-T nor the concentration and metabolism of α-T. These pathways appear tightly regulated, most probably to keep high steady-state blood ratios α-T to γ-T and γ-CEHC to α-CEHC.     

Benthic marine flora in the Tuscan Archipelago. A first contribution: Isles of Capraia,Elba, Formiche di Grosseto,Giglio, Scoglio d'Africa,Montecristo and Giannutri

Abstract

Benthic marine flora of Tuscan Archipelago has been studied. Several samples were collected along five islands and some rocks. This paper is a compendium of new and already published data, in which 267 species, varieties, forms and stadia of algae and seagrasses are listed: 5 Bangiophyceae, 182 Florideophyceae, 45 Phaeophyceae, 6 Chlorophyceae, 28 Bryopsidophyceae, 1 Angiospermae.     

Dispersione anemofila di polline in Valle Padana

Abstract

Anemophylus dispersal of pollen grains in the Po Valley.—Results of phenological and aerobiological measurements with Castanea sativa pollen are presented. The data concerning the dispersal of this pollen in the Po Valley, show some features of the transport over hundred kilometer distances and give useful suggestions for application research.     

Aphyllophorales del Bosco della Mesola (Ferrara)

Abstract

Aphyllophorales from Mesola Forest (Ferrara) Italy—The present check-list is the first contribution to the knowledge of Aphyllophorales growing in the area of the Mesola Forest. The paper deals with 72 species of Aphyllophorales collected during the years 1980-1983. A further contribution will complete the picture of the Aphyllophorales flora which is particularly interesting and abundant in the forest.

Some of the species listed in the present paper are quite interesting since they are uncommon: Meruliopsis hirtellus and Oxyporus latemarginatus are new to Italy; Flaviporus semisupiniformis is the first European finding and the second world collection.     

Note floristique et repartition de Rhodophycees rares (Kallymeniacees et Sebdeniacees) de la Mediterranee occidentale

Abstract

Floristic notes and geographical distribution of some rare Rhodophyta (Kallymeniaceae and Sebdeniaceae) of the western Mediterranean. Callophyllis laciniata, Kallymenia requienii and Kallymenia lacerata (Kallymeniaceae) and Sebdenia rodrigueziana (Sebdeniaceae) are recorded for the first time in the bay of Naples. For each species systematic and distribution data are also given.     

Contributo All'Embriologia Delle Plumbaginaceae (con 103 figg. nel testo)

Riassunto

L'A. stabilisce che in Plumbago capensis Thunb., accanto allo sviluppo secondo lo schema del tipo Plumbago, si riscontra, con bassissima frequenza, un nuovo tipo di sviluppo di gametofiti 7-nucleati bipolarizzati con oosfera di natura sporiale.

Stabilisce inoltre che in Statice Limonium L. lo sviluppo del gametofito femminile avviene esclusivamente secondo il tipo Euphorbia dulcis, mentre in Armeria vulgaris W. var. maritima (Miller) Willd. esiste associazione dei due tipi di sviluppo Adoxa ed Euphorbia dulcis nel rapporto approssimativo del 3%.

Mette in evidenza che la triploidia dei nuclei calazali, caratteristica dei gametofiti di tipo Euphorbia dulcis, può determinarsi secondo due distinte modalità : o per coalescenza dei tre fusi calazali durante la terza divisione dello sviluppo (Statice Limonium), o per un processo di vera e propria cariogamia dei tre nuclei sporiali quiescenti durante lo stadio di polarizzazione 1+3 con conscguente formazione durante la storia dello sviluppo di uno stadio binucleato secondario (Armeria vulgaris var. maritima).

Riconferma infine per questa ultima pianta il numero aploide dei cromosomi n = 9.     

Studio preliminare sulla tipologia della vegetazione sommersa del Canale di Sicilia e isole vicine

Abstract

Preliminary studies on the marine phythobenthic communities in the Straits of Sicily and adjacent islands. — The results of algological researches carried out by the Gruppo di Algologia of the S.B.I. in the Straits of Sicily and adjacent islands are reported. 288 species have been collected, 275 of which have been identified: 160 were Rhodophyta, 62 Phaeophyta, 32 Chlorophyta, 16 Cyanophyta and 2 Angiospermae. The vegetational research leads to the following conclusions: 1 - the harbour areas (Pantelleria, Malta: loc. 1 and 11) show a nitrophile vegetation, particulary near La Valletta where an almost pure population of Pterocladia pinnata is found; 2 - there are important biogeographical differences between Pelagie islands (Lampedusa, Linosa) and Pantelleria. In fact the former ones have an algal flora composed mostly of eastern mediterranean species, whilst the latter shows strong affinities with the north-african basin, as is demonstrated by the rich well developed belt of Cystoseira sedoides; 3 - several species of atlantic origin, such as Callophyllis laciniata, Peyssonnelia coriacea, P. inamoena and Castagnea chordariaeformis, have been found on the banks (loc. 3, 6, 7).