Does certified organic farming reduce greenhouse gas emissions from agricultural production? Reply to Muller et al

In this comment I respond to the criticisms put forth by Muller et al. It is my assessment that the authors’ make useful suggestions for future analyses. However, their conclusion regarding the invalidity of my results are based on a misconception of the goals and data used in my article.     

An assessment of the effectiveness of a large,national-scale invasive alien plant control strategy in South Africa

This paper presents an assessment of a large, national-scale alien plant control program that has operated in South Africa for 15 years. We reviewed data from three national-level estimates of the extent of invasion, records of the costs and spatial extent of invasive species control operations, assessments of the effectiveness of biological control, and smaller-scale studies. The 19 most important invasive taxa, mainly trees, in terrestrial biomes were identified. The effectiveness of control efforts on the extent of invasion of these taxa was assessed. Control costs over 15 years amounted to 3.2 billion rands (US$457 million), more than half of which was spent on 10 taxa, the most prominent being in the genera Acacia, Prosopis, Pinus and Eucalyptus. Despite substantial spending, control operations were in many cases applied to a relatively small portion of the estimated invaded area, and invasions appear to have increased, and remain a serious threat, in many biomes. Our findings suggest that South Africa’s national-scale strategy to clear invasive alien plants should be substantially modified if impacts are to be effectively mitigated. Rather than attempting to control all species, and to operate in all areas, a more focused approach is called for. This would include prioritising both the species and the areas, and setting goals and monitoring the degree to which they are achieved, within a framework of adaptive management. A greater portion of funding should also be directed towards biological control, where successes have been most notable.     

Wound healing in potato tuber tissue. 2. Varietal and anatomical variation

Summary The wound healing potential of 15 UK maincrop potato cultivars was assessed from the ability of discs of cortical and medullary tissue to become resistant to the loss of water vapour, as their surfaces suberized. Varietal rankings were moderately consistent over four experiments in two years, with cvs Désirée, Bintje and Pentland Hawk showing rapid healing and Majestic, Redskin and Pentland Crown rather slow healing. Wound healing rates in cortical and medullary tissue were generally similar. Since fast wound healing is not the dominant mechanism of resistance to disease, correlations with established ratings for resistance to individual diseases were not found, but some protection against a broad spectrum of storage diseases is likely. Wound healing rankings correlated with varietal resistance to mechanical damage.

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Zusammenfassung Die Versuche sollten sortenbedingte Unterschiede bei Wundheilungs-Raten demonstrieren. Ausserdem galt es herauszufinden ob sich Unterschiede im Wundheilungs-Potential zwischen Rinden- und Markgewebe ergeben, wodurch sich die relative Bedeutung von flachen gegenüber tiefen Wunden darstellen würde. Der Anstieg in der internen Widerstandsf?higkeit im Hinblick auf Verlust von Wasser-Dampfdruck von Scheiben von Knollengewebe, ein Mass für die Suberinisierung an Wundoberfl?chen, wurde über 6–9 Tage in vier Versuchen über zwei Lagerperioden verfolgt. Die 15 untersuchten sp?ten Kartoffelsorten zeigten betr?chtliche sortenbedingte Abweichungen in allen vier Experimenten (Tabellen 1 und 2). Zwischen den beiden Perioden waren die Schwankungen nur gering, ebenso zwischen den Untersuchungen im Herbst und im Frühjahr (Tabelle 3). Die H?he des Wasserverlustes bei Rinden- und Markgewebe waren im wesentlichen gleich (Tabelle 2) und korrelierten zwischen den Sorten (r=0,84,P<0,001). In den ersten 4–5 Tagen der Inkubation entwickelte sich die interne Widerstandsf?higkeit gegen Wasserverlust z?gernd, bei ungef?hr 6 Tagen dann schneller (Abb. 1). Sowohl das Ausmass des schnelleren Anstiegs als auch die Zeit des Beginns bestimmten den generellen Grad an Resistenz gegen Wasserverlust über die gesamte Inkubationsperiode (Abb. 1). Sorten mit rapider Wundverheilung in diesen Untersuchungen, z.B. Désirée und Bintje, befanden sich unter denjenigen, welche von Blight & Hamilton (1974) mit geringer Anf?lligkeit gegen mechanische Besch?digung eingestuft worden waren.

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Résumé Le but de cette étude est de mettre en évidence l'importance des variations dans le taux de cicatrisation des blessures selon les variétés et de rechercher s'il existe une différence dans le potentiel de cicatrisation entre les tissus corticaux et médullaires qui pourraient déterminer l'importance relative des blessures légères et profondes. L'augmentation de la résistance interne à la perte en vapeur d'eau à partir de lamelles de tissus de tubercules, comme mesure de subérisation des surfaces blessées, a été suivie pendant 6 à 9 jours dans 4 expérimentations au cours de deux campagnes de conservation. Les 15 principales variétés testées ont montré un degré variétal important dans les 4 essais (tableau 1 et 2). Le classement des variétés n'a guère varié d'une année à l'autre et entre automne et printemps (tableau 3). Les taux de perte en eau des tissus médullaire et cortical sont en général équivalents (tableau 2) et correlés avec les variétés (r=0,84,P<0,001). La résistance interne à la perte en eau évolue lentement les 4–5 premiers jours d'incubation, et plus rapidement après 6 jours environ (fig. 1). La variation dans la phase rapide, et dans sa date de démarrage détermine le niveau global de résistance à la perte en eau pour toute la période d'incubation (fig. 1). Les variétés qui montrent une évolution rapide de cicatrisation dans cette étude, telles que Désirée et Bintje, sont parmi celles estimées par Blight & Hamilton (1974), qui présentent une faible sensibilité à l'endommagement mécanique.

     

Genetic associations between feed efficiency measured in a performance test station and performance of growing cattle in commercial beef herds

Interest in selection for improved feed efficiency is increasing, but before any steps are taken toward selecting for feed efficiency, correlations with other economically important traits must first be quantified. The objective of this study was to quantify the genetic associations between feed efficiency measured during performance testing and linear type traits, BW, live animal value, and carcass traits recorded in commercial herds. Feed efficiency data were available on 2,605 bulls from 1 performance test station. There were between 10,384 and 93,442 performance records on type traits, BW, animal value, or carcass traits from 17,225 commercial herds. (Co)variance components were estimated using linear mixed animal models. Genetic correlations between the muscular type traits in commercial animals and feed conversion ratio (-0.33 to -0.25), residual feed intake (RFI; -0.33 to -0.22), and residual BW gain (RG; 0.24 to 0.27) suggest that selection for improved feed efficiency should increase muscling. This is further evidenced by the genetic correlations between carcass conformation of commercial animals and feed conversion ratio (-0.46), RFI (-0.37), and residual BW gain (0.35) measured in performance-tested animals. Furthermore, the genetic correlations between RFI and both ultrasonic fat depth and carcass fat score (0.39 and 0.33, respectively) indicated that selection for improved RFI will result in leaner animals. It can be concluded from the genetic correlations estimated in this study that selection for feed efficiency will have no unfavorable effects on the performance traits measured in this study and will actually lead to an improvement in performance for some traits, such as muscularity, animal price, and carcass conformation. Conversely, this suggests that genetic selection for traits such as carcass quality, muscling traits, and animal value might also be indirectly selecting for more efficient animals.     

Evaluation of cytokine mRNA expression in bronchoalveolar lavage cells from horses with inflammatory airway disease

Inflammatory airway disease (IAD) is a common disorder of performance horses and is associated with poor performance and accumulation of mucus and inflammatory cells in lower airway secretions. Horses with IAD frequently have increased relative counts of neutrophils in bronchoalveolar lavage fluid (BALF); less commonly relative counts of eosinophils and/or mast cells may be increased. The aetiopathogenesis of IAD is unknown and may involve innate and/or acquired immune responses to various factors including respirable dust constituents, micro-organisms, noxious gases and unconditioned air. The molecular pathways and role of the immune system in the pathogenesis of IAD remain poorly defined and it is unknown whether polarised T cell responses occur in the disease, as have been reported to occur in equine recurrent airway obstruction and asthma in humans. Elucidating cytokine responses that develop in horses with IAD may allow a greater understanding of the possible aetiopathological pathway(s) involved and could contribute to development of novel treatments. We compared the mRNA expression of tumour necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin (IL)-1β, IL-2, IL-4, IL-8, IL-13, IL-17 and IL-23 in cell pellets extracted from BALF of horses with IAD (n=21) and horses free of respiratory tract disease (n=17). Horses with IAD had significantly increased levels of TNF-α, IL-1β and IL-23 mRNA; no significant differences in the other cytokine mRNAs were detected. The results of this study indicate that IAD of horses is associated with increased mRNA expression of pro-inflammatory cytokines in BALF cells, which may reflect stimulation of the innate immune responses to inhaled antigens. There was no evidence of a polarised T-cell cytokine response suggesting hypersensitivity responses may not be involved in the aetiopathogenesis of IAD.     

The left lateral projection is comparable to horizontal beam radiography for identifying experimental small volume pneumoperitoneum in the canine abdomen

Nontraumatic spontaneous pneumoperitoneum suggests the presence of gastrointestinal perforation; early detection can be lifesaving. Horizontal beam projections have been reported to be more sensitive than standard radiographic views for detecting small volumes of free peritoneal gas. This prospective, experimental, analytical study compared both left lateral (LL) and ventrodorsal (VD) standard views to horizontal beam projections for detecting small volumes of artificially induced pneumoperitoneum in live dogs. The effect of radiology training on accurate detection of small amounts of free peritoneal air was also assessed. Fourteen dogs had four radiographic projections taken after injection of 0, 2.5, 5, and 10 mL of cumulative air into their abdominal cavities. Radiographs were interpreted individually by three American College of Veterinary Radiology‐certified radiologists and three small animal internship‐trained veterinarians who were blinded to the air volume injected. At 2.5 and 10 mL of air injected, the LL projection had highest odds of an accurate response (odds ratio [OR] = 2.4 and 99.0 when compared to VD horizontal and VD projections, respectively). At 5 mL of air injected, the lateral horizontal (LH) projection had the highest odds of an accurate response (OR = 3.2 compared to VD horizontal). The LL projection was not significantly different from the LH projection at all volumes of air injected. Board certification led to higher odds of accurate responses at volumes of 5 (OR = 2.2) and 10 mL (OR = 3.6), as compared to nonspecialist veterinarians. Overall, LH and standard LL appeared to be the most useful radiographic projections for detection of small amounts of free peritoneal gas.     

Fucoidan Structure and Its Impact on Glucose Metabolism: Implications for Diabetes and Cancer Therapy

Fucoidans are complex polysaccharides derived from brown seaweeds which consist of considerable proportions of L-fucose and other monosaccharides, and sulphated ester residues. The search for novel and natural bioproduct drugs (due to toxicity issues associated with chemotherapeutics) has led to the extensive study of fucoidan due to reports of it having several bioactive characteristics. Among other fucoidan bioactivities, antidiabetic and anticancer properties have received the most research attention in the past decade. However, the elucidation of the fucoidan structure and its biological activity is still vague. In addition, research has suggested that there is a link between diabetes and cancer; however, limited data exist where dual chemotherapeutic efforts are elucidated. This review provides an overview of glucose metabolism, which is the central process involved in the progression of both diseases. We also highlight potential therapeutic targets and show the relevance of fucoidan and its derivatives as a candidate for both cancer and diabetes therapy.     

Getting lost in the matrix? On how the characteristics and arrangement of linear landscape elements influence ecological connectivity

Landscape Ecology - Linear landscape elements (LLEs) such as ditches and hedgerows can increase the ecological connectivity of habitat embedded within agricultural areas by acting as corridors for...