Using 3D animations to teach intracellular signal transduction mechanisms: taking the arrows out of cells

Traditional methods of teaching intracellular biological processes and pathways use figures or flowcharts with the names of molecules linked with arrows. Many veterinary students, presented with such material, simply memorize the names or chemical structures of the molecules and are then likely to forget the material once the examination is completed. To address this problem, the authors designed, created, and field-tested new teaching media that incorporate realistic three-dimensional (3D) animations depicting the dynamic changes that occur in intracellular molecules during cellular activation. Testing found that veterinary students taught using traditional teaching media (e.g., lectures, handouts, textbooks) are proficient in memorizing the names and order of intracellular molecules but unable to appreciate the interactions between these elements or their spatial relationships within cells. In contrast, more than 90% of veterinary students taught using 3D animations not only recall the facts about the intracellular elements but also develop accurate mental images of the interactions among these molecules and their spatial relationships. These findings strongly suggest that the comprehension of complex biological processes by veterinary students can be enhanced by the use of dynamic 3D depictions of these processes in the classroom.     

Occurrence of Grapevine Pinot gris virus in Friuli Venezia Giulia (Italy): field monitoring and virus quantification by real‐time RT‐PCR

Since 2003 the presence of a new syndrome characterized by symptoms of stunting, chlorotic mottling, leaf deformation, reduced yields and quality has been reported in some white berry varieties of Vitis vinifera in Trentino‐Alto Adige and Friuli Venezia Giulia vineyards. The identification of a new virus, provisionally called Grapevine Pinot gris virus (GPGV), in a cv. Pinot gris vine suggested an association between this new syndrome and the virus presence (Giampetruzzi et al., 2012), however the contemporary presence of GPGV in both symptomatic and asymptomatic plants has still to be explained. In this work, a large‐scale monitoring over a 3‐year period (2012–14) of Friuli Venezia Giulia vineyards and nurseries has shown a widespread presence of GPGV in symptomatic plants and also in asymptomatic vines, even if at a slightly lower percentage. Quantitative analyses of the virus titer revealed a great variability in the viral content of both symptomatic and asymptomatic plants but the mean GPGV quantity in symptomatic vines was significantly higher than in asymptomatic plants.     

Physical Properties of Extruded Wheat Starch-Additive Mixtures

The effects of the addition of fatty acids, monoglycerides (MG), and wheat germ oil (WGO) on the level of crystallinity and the crystalline structure of extrusion-cooked wheat starch have been studied using twin-screw extruders. Measurements of water solubility and water absorption indices were made on the extrudates, together with specific mechanical energy (SME) consumption and die pressure for the extruder. MG and the fatty acids added to a level of 4% caused an increase in V_hydrate type crystallinity. WGO addition to a level of 8% caused no change in crystallinity, although the E_hydrate type was favored at lower moisture contents. All additives caused a decrease in SME and an increase or maximum in die pressure. WGO behaved differently than MG and fatty acids in that its addition caused the water solubility index and expansion to increase, as previously observed for other oils added to flours.     

Prolonged storage of potato seeds

Summary A long-term storage experiment has shown that viability of potato seeds is preserved by either cool storage (5°C) or dry storage (over silica-gel). Seeds which lose viability in ordinary air storage in about 6 years can thus be preserved for at least 8 years and probably much longer. Dry storage is particularly effective in preserving dormancy, initially deeply dormant seeds still retaining some dormancy after as long as 8 years. Low temperature, by contrast, did not materially influence the rate of natural decline of dormancy with time.

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Zusammenfassung Ein langfristiger Lagerungsversuch mit Samen von kultivierten Kartoffeln wird beschrieben. Es wurden 64 Verfahren angewendet: diploid vs. tetraploid (Andigena-Gruppe); Luft- vs. Troekenlagerung; warme vs. kühle (5 C) Lagerung; und 8 Lagerunsperioden (0, 2, 4, 8, 16, 32, 64, 90 Monate). Die Hauptergebnisse sind in Tabelle 1 enthalten. Varianzanalysen in Tabelle 2 und eine Zusammenfassung der Entwicklungstendenzen betreffend Keimruhe in Tabelle 3. Ergebnisse: Die diploiden Samen hatten eine kürzere Ruhezeit und waren weniger langlebig als die tetraploiden Samen, besonders unter feuchten und warmen Bedingungen (Tabelle 1); Trockenlagerung f?rderte die Langlebigkeit (mindestens unter warmen Bedingungen) und bewahrte die Keimruhe; Kühllagerung f?rderte die Langlebigkeit (besonders uner feuchten Bedingungen), hatte aber keinen signifikanten Einfluss auf die Keimruhe; dagegen bestand ein Hinweis (Tabelle 1), dass Kühllagerung eine leichte Verl?ngerung der Keimruhe von feuchten Samen bewirkt; es gab Anzeichen von leichter ‘sekund?rer Keimruhe’ nach einigen Jahren der Lagerung. Das Hauptergebnis war, dass die Langlebigkeit entweder durch kühle oder durch trockene Lagerung erhalten werden kann, aber dass bei Anwendung von Trockenlagerung eine Technik zur Brechung der Keimruhe notwendig w?re. Die Bezichung zwischen Keimruhe and Langlebigkeit ist noch unklar; es kann sien, dass die Langlebigkeit erst abzunehmen beginnt, wenn die Keimruhe vorbei ist. In diesem Falle w?ren für sehr lange Lagerungszeiten trockene Bedingungen besser als kühle. Diese vorl?ufige Schlussfolgerung geht jedoch nicht aus den hier vorgelegten Angaben hervor und verlangt eine unabh?ngige Untersuchung.

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Résumé L'auteur décrit une expérience de conservation de longue durée de semences de pommes de terre cultivées. Il applique 64 traitements: diplo?de et tétraplo?de (Groupe Andigena); conservation à l'air et conservation sèche; conservation chaude et conservation froide (5 C); huit durées de stockage (0, 2, 4, 8, 16, 32, 64, 90 mois). Les principaux résultats sont donnés dans le Tableau 1, les analyses de la variance dans le Tableau 2 et le résumé des orientations de la dormance dans le Tableau 3. Ces résultats sont les suivants: les diplo?des ont une moindre durée de dormance et une durée moins longue de vie que les tétraplo?des spécialement en conditions humides et chaudes (Tableau 1); la conservation sèche favorise la longévité (au moins dans les conditions chaudes) et préserve la dormance; la conservation froide favorise la longévité (particulièrement en conditions humides) mais n'a pas d'effet significatif sur la dormance; il y a cependant une indication (Tableau 1) que la conservation froide tend légérement à prolonger la dormance des semences humides; il y a des signes d'une légère ‘dormance secondaire’ après plusieurs années de conservation. La principale conclusion est que la longévité peut être sauvegardéc par une conservation froide ou sèche mais que, en conservation séche, une technique pour rompre la dormance serait nécessaire. La relation entre la dormance et la longévité n'est pas encore claire; il se peut que la longévité commence à décliner seulement quand la dormance est passée, auquel cas les conditions séches seraient meilleures que les conditions froides pour une conservation très prolongée. Cette conclusion supposée ne découle cependant pas des données présentées ici et nécessite une expérimentation séparée.

     

THE DISTRIBUTION OF LEAF AREA AND LIGHT INTENSITY WITHIN WHEAT CROPS DIFFERING IN ROW DIRECTION, ROW SPACING AND RATE OF SOWING; A CONTRIBUTION TO THE STUDY OF UNDERSOWING PASTURE WITH CEREALS

The distribution of leaf area and light intensity within wheat crops differing in row direction, row spacing and rate of sowing is described. Regardless of the manner of planting, 75% of the total leaf area was found within a band 31/2 in. wide, centred on the centre of the row. Light penetration within crops spaced at 14 in. was greater than within those spaced at 7 in. Light penetration within rows running N.–S. was more uniform and higher, particularly around noon, than within rows running E.-W. Within N.-S. rows the position midway between rows received the highest amount of light, but light decreased on either side until it was least beneath the rows. Within E.-W. rows at 14 in. spacing, maximum light was recorded at 101/2 in. on the southern side of a row, decreasing progressively as the row was approached.     

Limnological changes in a sub‐tropical shallow hypertrophic lake during its restoration: two years of a whole‐lake experiment

1. Lake Rodó is a turbid system, a condition attributed to algal biomass. The proximal source of the eutrophication was stormwater discharges from an ill‐defined urban area. This paper describes an attempt to restore the water quality of Lake Rodó, the first time this has been done in Uruguay. In spring 1996 it was drained, sediments were removed and stream inputs were diverted. Groundwater was used to re‐fill the lake. Due to its high nutrient concentration a re‐circulation system was designed, pumping water from associated pools covered with free‐floating plants. 2. After the lake was refilled, the system was characterized by oxygen saturation or over‐saturation, neutral to basic pH, and high phosphorus, nitrogen and silicate concentrations. Ratios of total nitrogen (TN):total phosphorus (TP) and chlorophyll a (Chl a):TP indicated that phosphorus was the primary limiting nutrient during the period of groundwater supply. Once groundwater pumping had ceased, there was a decrease in TN:TP and Chl a:TP ratios, suggesting N‐limiting conditions prevailed in some periods. 3. Before restoration, the phytoplankton community was dominated year‐round by Planktothrix agardhii; since restoration the community has been more diverse. This change has favoured grazing by mesozooplankton, and the onset of clear‐water phases in spring. 4. Abundant populations of small omnivorous fish maintained a high predation pressure on zooplankton, restricting the abundance of large‐bodied herbivores, which, in turn, allowed an increase in phytoplanton biomass and a decrease in water transparency. Based on this observation, together with the phosphorus concentration and the low abundance of filamentous cyanobacteria compared with previous studies, we suggest that top‐down control has played a key role in increasing transparency in Lake Rodó. 5. A nutrient reduction programme, by the mechanical harvest of floating plants, and a removal of small omnivorous fishes and stocking strictly with piscivores, could be key factors in the achievement of a stable clear‐water phase. However, if blooms of Microcystis or other similar genera occur in summer, additional measures (e.g. reduction of the hydraulic residence time) will be needed to improve water transparency. Copyright © 2001 John Wiley & Sons, Ltd.     

Degradation of AM Nitrification Inhibitor in Soil of Subtropical Region

The aim of the study was to evaluate the degradation and persistence of 2-amino 4-chloro 6-methyl pyrimidine (AM), nitrification inhibitor at 1 and 2 µg g^?1 application rates in soil. The extraction of AM was done by QuEChER’s (Quick, Easy. Cheap. Rugged and Safe) method and the quantitative analysis by high-performance liquid chromatography (HPLC). AM decreased with time at both the levels of application with the decline being faster in the beginning up to 7 d. Dissipation of AM occurred in a single phase with the persistence data fitting well to the first-order kinetics. Half-lives of AM were determined to be 14.33 and 16.7 d at 1 and 2 µg g^–1 levels application rates. Since AM remains effective for an adequate period of time, it can be used for increasing efficiency of nitrogenous fertilizers in rice–wheat cropping systems as well as a safeguard for controlling environmental pollution in subtropical soils.     

Redescription of Eimeria dorcadis Mantovani, 1966 (Apicomplexa: Eimeriidae) from the dorcas gazelle (Gazella dorcas) in Saudi Arabia

Eimeria dorcadis Mantovani, 1966 is redescribed from dorcas gazelle (Gazella dorcas (L.)) from Saudi Arabia. Oocysts were detected in 7 out of 22 faecal samples (32%) using floatation method. The sporulated oocysts are cylindrical, slightly flattened at the micropylar pole, measure in average 32 x 19 microm (27-36 x 16-24 microm), length/width ratio being 1.7 (1.5-2.1). Oocyst wall is 1.2 microm thick, smooth, double-layered; outer layer is slightly thicker, light blue in colour; inner layer brownish, with micropyle in the inner layer and apparently continual outer one, measures 2.2 microm, but lacks a micropylar cap. The sporocyst elongate-ellipsoidal, measures 14 x 8 microm (12-17 x 6-9 microm), length/width ratio being 1.8, with sporocyst residuum as circular compact, coarse, refractile granules. Stieda body is present, while substieda body is absent. Sporozoites banana-shaped, measure 11 x 2.5 microm, each with a large spheroidal refractile body at the wider pole. Sporulation time is 2-3 days at 25 +/- 2 degrees C.