A rapid extensigraph protocol for measuring dough viscoelasticity and mixing requirement

The extensigraph is particularly useful in characterizing dough viscoelastic properties; however, testing throughput for standard method is low due to the prerequisite for farinograph water absorption, long dough resting and milling to prepare large amounts of flour. Therefore, a rapid extensigraph method was developed that reduced sample size (165 g wheat) for milling and more than tripled throughput. Wheat is milled in Quadrumat Junior mill with a modified sieving system. The resulting flour (100 g) was mixed with a pin mixer at constant water absorption to allow the evaluation of wheat genotypes at the absorption level they are expected to perform. Dough was subsequently stretched by an extensigraph after 15 min of floor time and 30 min resting. Strong correlations for extensigram R_max (r > 0.93), extensibility (r > 0.64) and area (r > 0.88) were found for the proposed method compared to the standard method. Mixing parameters (time and energy) obtained during dough preparation provided further information about dough strength and mixing requirement. By significantly reducing sample size requirement and increasing testing throughput, this rapid extensigraph method can be widely adopted in milling and baking industry and meets the need for a fast evaluation of dough strength in breeding trials.     

Kernel vitreousness and protein content: Relationship,interaction and synergistic effects on durum wheat quality

Four sets of durum samples were used in this study to further understand the interrelationships among hard vitreous kernels (HVK), protein content, and pigment concentration, with a focus on the interaction and synergistic effects of protein content and vitreousness on durum quality. HVK level increases with higher protein content in the range of 9.5–12.5%, but this relationship is less evident in durum samples with high protein content (12.5–14.5%). Both protein content and kernel vitreousness can significantly affect durum milling quality. White starchy kernels (WSK) in low protein durum have a very detrimental impact on milling and pasta processing quality, but high protein content can mitigate the adverse impact of WSK on durum quality. Although protein content plays a dominant role, higher HVK might contribute positively to pasta firmness. There was no significant difference in yellow pigment content between HVK and WSK. However, pigment loss from semolina to dough was higher for WSK than HVK. Despite the difference in protein content, HVK and WSK have little difference in gluten strength. The monomeric protein was preferentially accumulated in HVK. The glutenin proteins of HVK and WSK were similar in the ratios of 1Bx/1By and HMW/LMW-GS.     

A new lean no time test baking method with improved discriminating power

In response to customer concerns related to gluten strength in commercial baking, the Canadian Grain Commission assessed whether the Canadian Short Process (CSP) test bake method was generating useful data related to intrinsic strength of wheat varieties. Assessment of CSP loaf volume data for Canadian variety trials spanning 2003 to 2013 showed very little correlation with dough strength parameters as measured by farinograph and extensigraph. A lean no time (LNT) test baking method was developed that can better discriminate genotypes and provide objective indicators of the effect of intrinsic dough strength on baking quality. From early method development, through method validation and verification using diverse sets of samples targeting different Canadian wheat classes and grown in three different crop years, results showed the LNT method to be more discriminating and easily adopted by other laboratories. In 2015, the LNT method was adopted as the method of choice in future Canadian variety registration trials. The LNT method is fast, simple and well-suited to high throughput test baking conditions encountered in the evaluation of large numbers of breeder lines. A new objective parameter, loaf top ratio, was also introduced and found to correlate well with dough strength and dough handling properties.     

Habitat associations of the Threatened pugnose minnow (Opsopoeodus emiliae) at the northern edge of the species range

Pugnose minnow (Opsopoeodus emiliae) is a small, reclusive species that is widespread in North America, but is one of the rarest fishes in Canada, found in less than 12 known localities in southwestern Ontario. In contrast to most pugnose minnow populations across the global range, Canadian populations are primarily found in turbid systems, potentially indicating persistence in suboptimal conditions. We used data from a multi-gear species and habitat survey in the Canard River, Ontario, a system dominated by agricultural inputs and the best-known capture site of the species in Canada, to parameterise multi-gear occupancy models for understanding the relationship between pugnose minnow occupancy and microhabitat features, including the role of turbidity. Almost 300 pugnose minnow were captured, representing the largest single collection of the species in Canadian history. The best occupancy model indicated that the probability of pugnose minnow occupancy was highest in the deepest sites with the lowest water clarity (i.e. high turbidity); however, competing models suggested that occupancy was highest at sites with wild celery (Vallisneria americana) and higher water clarity, signifying that habitats with low turbidity may be utilised if sufficient physical cover exists. Together, our results suggest that Canadian pugnose minnow populations occupy and potentially favour turbid conditions, possibly to avoid visual predators in clearer habitats. It remains uncertain whether this abiotic association represents a long-term, viable, local adaptation or whether persistence of pugnose minnow in the Canard River is at risk unless significant water quality improvements can be made.     

不同产地西洋参氨基酸种类及含量分析

为研究不同种植区西洋参氨基酸的含量和品质，按食品安全国家标准GB/T5009.124-2016，对加拿大多伦多市、陕西省留坝县、吉林省抚松县、山东省文登市来源的4 a生西洋参进行氨基酸种类和含量测定及对比分析。各产地西洋参均检测出17种氨基酸，其中含有人体必需的赖氨酸、蛋氨酸、异亮氨酸、苯丙氨酸、亮氨酸、苏氨酸、缬氨酸和半必需氨基酸精氨酸；含有蛋氨酸、亮氨酸、异亮氨酸、苯丙氨酸、赖氨酸、天冬氨酸、甘氨酸、谷氨酸和精氨酸等8种药用氨基酸。人体必需氨基酸及药用氨基酸含量对比分析结果表明，加拿大多伦多市来源西洋参的这两类氨基酸含量最高，分别为46.20 mg/g 和61.93 mg/g，占总氨基酸含量的 54.0%和72.3%，其次是陕西省留坝县来源的西洋参，分别为45.70 mg/g和61.63 mg/g，占总氨基酸含量的51.9%和70.0%。主成分分析及综合评价结果表明，从氨基酸含量及营养均衡性角度来看，陕西省留坝县西洋参是最接近原产地加拿大的西洋参。     

Generalized height–diameter models—an application for major tree species in complex stands of interior British Columbia

Using permanent sample-plot data, selected tree height and diameter functions were evaluated for their predictive abilities for major tree species in complex (multiple age, size and species cohort) stands of interior British Columbia (BC), Canada. Two sets of models were evaluated. The first set included five models for estimating height as a function of individual tree diameter, the second set also included five models for estimating height as a function of individual tree diameter and other stand-level attributes. The inclusion of the BAL index (which simultaneously indicates the relative position of a tree and stand density) into the base height–diameter models increased the accuracy of prediction for all species. On average, by including stand level attributes, root mean square values were reduced by 30.0 cm. Based on the residual plots and fit statistics, these models can be recommended for estimating tree heights for major tree species in complex stands of interior BC. The model coefficients are documented for future use.     

中欧山松大小蠹的生物学特性及在加拿大BC省的发生状况

从分布及寄主,形态特征及生活史,为害特性对中欧山松大小蠹的生物学特性作了介绍。继后对此虫害在加拿大BC省为害的现状及该国目前对中欧山松大小蠹的研究进行了论述。     

Intergeneric hybrids and an amphiploid between Elymus canadensis and Psathyrostachys juncea

Summary Fifty four hybrid plants between Elymus canadensis and Psathyrostachys juncea were obtained by handpollination and embryo culture. The average cross compatibility between both species was 31.2 percent. One amphiploid plant was induced by colchicine treatment. The hybrid and amphiploid plants resembled P. juncea in appearance but showed a higher plant height and dry matter yield than the parents. The hybrids showed extremely low pollen stainability and were completely sterile. With the exception of one plant (2n=3x+1=22), all hybrid plants were allotriploids (SHN, 2n=3x=21). The amphiploid plant (SSHHNN, 2n=6x=42) showed 58.9% pollen stainability and 11.6% seed fertility.Mean chromosome associations of the hybrids and amphiploid at metaphase I were 0.02IV+0.06III+2.03II+16.91I and 0.07III+18.00II+5.85I, respectively. Lagging chromosomes, chromosome bridges, abnormal cytokinesis, and micronuclei were occasionally observed at the anaphase, telophase, or tetrad stage.     

Impacts of chronic marine oil pollution and the murre hunt in Newfoundland on thick-billed murre Uria lomvia populations in the eastern Canadian Arctic

We developed a deterministic and stochastic age-based matrix projection population model to assess and quantify the impact of mortality caused by chronic oil pollution and legal hunting on thick-billed murre Uria lomvia populations breeding and wintering in eastern Canada. We calculate the potential population growth rate in the absence of anthropogenic mortality sources using a modeling technique that translates absolute number of birds killed from anthropogenic mortality to potential survival rates in the absence of these anthropogenic impacts. The intrinsic growth rate of the deterministic matrix based on vital rates from Coats Island (λ_d=1.0102), as well as the stochastic growth rate (λ_s=1.0098, 95% C.I. 0.9969-1.0226), matched observed population trends. Hunting mortality reduced population growth rate by 0.020 (0.012-0.039), oiling mortality reduced population growth rate by 0.025 (0.012-0.039). Combined these sources reduced the population growth rate by 0.047 (0.033-0.610). Although thick-billed murre populations are stable or slowly growing in eastern Canada, anthropogenic sources of mortality are reducing the ability of the population to grow, and increase vulnerability in these populations to changes in their environment and other pulse perturbations. Our modeling technique could be used to assess specific anthropogenic impacts on populations where a vital rates and numbers killed are known, but no long-term trend information is available.