Remote sensing imaging as a tool to support mulberry cultivation for silk production

In recent decades there has been an increasing use of remotely sensed data for precision agricultural purposes. Sericulture, the activity of rearing silkworm (Bombyx mori L.) larvae to produce silk in the form of cocoons, is an agricultural practice that has rarely used remote sensing techniques but that could benefit from them. The aim of this work was to investigate the possibility of using satellite imaging in order to monitor leaf harvesting in mulberry (Morus alba L.) plants cultivated for feeding silkworms; additionally, quantitative parameters on silk cocoon production were related to the analyses on vegetation indices. Adopting PlanetScope satellite images, four M. alba fields were monitored from the beginning of the silkworm rearing season until its end in 2020 and 2021. The results of our work showed that a decrease in the multispectral vegetation indices in the mulberry plots due to leaf harvesting was correlated with the different parameters of silk cocoons spun by silkworm larvae; in particular, a decrease in the Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) had high correlations with quantitative silk cocoon production parameters (R2 values up to 0.56, p < 0.05). These results led us to the conclusion that precision agriculture can improve sericultural practice, offering interesting solutions for estimating the quantity of produced silk cocoons through the remote analysis of mulberry fields.This research was funded by the Veneto Region, Measure 16.1-2 Programme of Rural Development for the Veneto Region, 2014-2020-DGR 2175 del 23/12/2016, grant number: “Decree n. 55 of 4th December 2017 of financing of the project Serinnovation.”

Effect of food and temperature on the development and silk production of Bombyx mori Linnaeus (Lepidoptera: Bombycidae).

Larven von Bombyx mori Linnaeus wurden mit verschiedenartiger Nahrung bei unterschiedlichen Temperaturen aufgezogen. Es wurde festgestellt, daß die Entwicklung bei 30°C am schnellsten und bei 20°C am langsamsten verlief, daß aber die ausgereiften Larven und Puppen bei 25°C am meisten wogen. Der Wassergehalt der gezogenen Puppen war bei 20°C höher als bei den beiden anderen Temperaturen. Auf Blättern von Maulbeersämlingen gezogene Larven entwickelten sich schneller als auf Blättern von gepfropften Varietäten gezogene. Die Puppenperiode war jedoch bei der ersteren Nahrung länger als bei der letzteren. Die langsamere Larvenentwicklung auf den gepfropften Varietäten war mit geringerem Larven- und Puppengewicht verbunden. Unabhängig von der Temperatur und der Güte der Nahrung waren Larven und Puppen von Weibchen immer schwerer als von Männchen. Die Überlebensquote der Raupen war bei 30°C niedriger als bei 20°C oder 25°C. Sie war ferner bei gepfropftem M. alba niedriger als bei jeder anderen Nahrung. Die Seidenproduktion der Raupen war bei 25°C am höchsten und bei 30°C am geringsten. Wenn die Larven auf Blättern von Maulbeersämlingen gezogen wurden, erzeugten sie mehr Seide als bei Aufzucht auf Blättern der gepfropften Varietäten. Weibliche Raupen erzeugten stets schwerere grüne Kokons als männliche. Die Seidenhülsen der schwereren weiblichen Kokons wogen jedoch nicht mehr als die der leichteren männlichen Kokons, außer bei der ungünstigen Temperatur von 30°C bei Nahrung von Sämlingen. Die Insekten legten die größte Anzahl von Eiern, wenn sie bei 25°C gezogen wurden, und die geringste Anzahl bei 30°C. Das Gewicht der Larven und Puppen bei 20°C unterschied sich nicht von dem bei 30°C, aber die bei 30°C geringere Fruchtbarkeit als bei 20°C hängt eindeutig damit zusammen, daß das Leben der Motten bei der ersteren Temperatur kürzer ist als bei der letzteren. Auf Blättern von Maulbeersämlingen gezogene Insekten legten signifikant mehr Eier als auf Blättern von gepfropften Varietäten gezogene. Das Leben im Reifestadium war auf gepfropftem M. alba kürzer als bei jeder anderen Nahrung. Im allgemeinen lebten die Männchen länger als die Weibchen.Larvae of Bambyx mari Linnaeus were reared on food of different qualities at different temperatures. - It was found that although the rate of development was highest at 30°C and lowest at 20°C, mature larvae and pupae weighed more at 25°C. Water content of pupae reared at 20°C was higher than that at the other two temperatures. Larvae reared on leaves from seedling varieties of mulbeny developed more quickly than those reared on leaves from grafted varieties. The pupal period, however, was longer on the former than on the latter food. The lower rate of larval development on grafted varieties was associated with decreased larval and pupal weights. Irrespective of temperature and quality of food, larvae and pupae of females were always heavier than those of males. The rate of survival among caterpillars was lower at 30°C than at 20°C or 25°C. It was also lower on grafted M. alba than on any other food. Silk production by caterpillars was highest at 25°C and lowest at 30°C. When larvae were reared on leaves from seedling varieties of mulberry, they produced more silk than those reared on leaves from graf ted varieties. Female caterpillars always produced heavier green cocoons than males. Silk shells from heavier female cocoons, however, did not weigh more chan those from lighter male cocoons, except at the unfavourable temperature of 30°C on seedling foods. Insects laid the highest number of eggs when reared at 25°C and the smallest number at 30°C. There was no difference in larval and pupal weights at 20°C and 30°C, but lower fecundity at 30°C than at 20°C was definitely associated with the fact that the life of the moths was shorter at the former than at the latter temperature. Insects reared on leaves from seedling mulberry laid significantly more eggs than those reared on leaves from grafted varieties. Adult life was shorter on grafted M. alba than on any other food. Generally the males lived longer than the females

Mechanical Processing of Hermetia illucens Larvae and Bombyx mori Pupae Produces Oils with Antimicrobial Activity

The aim of this work was to develop processing methods that safeguard the quality and antimicrobial properties of H. illucens and B. mori oils. We adopted a vegetable diet for both insects: leftover vegetables and fruit for H. illucens and mulberry leaves for B. mori. First, alternative techniques to obtain a good oil extraction yield from the dried biomass of H. illucens larvae were tested. Traditional pressing resulted to be the best system to maximize the oil yield and it was successfully applied to B. mori pupae. Oil quality resulted comparable to that obtained with other extraction methods described in the literature. In the case of B. mori pupae, different treatments and preservation periods were investigated to evaluate their influence on the oil composition and quality. Interestingly, agar diffusion assays demonstrated the sensitivity of Gram-positive Bacillus subtilis and Staphylococcus aureus to H. illucens and B. mori derived oils, whereas the growth of Gram-negative Pseudomonas aeruginosa and Escherichia coli was not affected. This study confirms that fat and other active compounds of the oil extracted by hot pressing could represent effective antimicrobials against bacteria, a relevant result if we consider that they are by-products of the protein extraction process in the feed industry

Impact of change in air temperature on the biological parameters of larvae and productivity of silkworm cocoons

Especially, the construction of special silkworm rooms near the mulberry yards, which are organized for harvesting mulberry silkworms several times a year, gives positive results. “…construction of special facilities for silkworm breeding, increasing the planting of mulberry seedlings on the edges of the farm, intensively continuing the activities aimed at ensuring the employment of the population due to the effective use of existing opportunities” are defined as urgent tasks. For this purpose, it is necessary to ensure that the area of rooms and special silkworm rooms selected for silkworm rearing by the silkworm rearing units of the homesteaders and farms involved in silkworm rearing is adequate, and when the silkworms pass from age to age, they should be thinned out, fertilized, and provided with sufficient quality feed. Summing up on the basis of the analyzed data, it is worth noting that during the period of silkworm rearing, full feeding of larvae during their youth, moderate air temperature in the silkworm room, smooth development of silkworms without becoming large and small, and vitality by ensuring that the biological indicators of the mulberry silkworm are high and the activity of the silk-secreting glands is increased, the productivity and yield characteristics of the cultivated silkworm cocoons are achieved

The Academic Robes of Graduates of the University of Cambridge from the End of the Eighteenth Century to the Present Day

The aim of this article is to examine the developments in the academic dress of the graduates of the University of Cambridge from the end of the eighteenth century (where Hargreaves-Mawdsley ended his account) to the present day. (Undergraduate dress has been largely a matter for college regulation at Cambridge, and thus does not come within our remit.) Without doubt, the most important development was the complete revision of the scheme in 1934, of which a very biased account is to be found in Franklyn’s Academical Dress of 1970; it does however have useful transcripts of the various Reports of the Council of Senate. This article will concentrate on the colours of the hoods and robes, and to an extent on the styles of the black gowns, but will not enter into discussion of the variations in the hood shape. We ignore also the ‘business’ or Congregation dress of doctors, as by about 1880 it had virtually disappeared from ordinary use. [Excerpt]

Silk and its composites for humidity and gas sensing applications

Silk fibroin (SF) is a natural protein largely used in the textile industry with applications in bio-medicine, catalysis as well as in sensing materials. SF is a fiber material which is bio-compatible, biodegradable, and possesses high tensile strength. The incorporation of nanosized particles into SF allows the development of a variety of composites with tailored properties and functions. Silk and its composites are being explored for a wide range of sensing applications like strain, proximity, humidity, glucose, pH and hazardous/toxic gases. Most studies aim at improving the mechanical strength of SF by preparing hybrids with metal-based nanoparticles, polymers and 2D materials. Studies have been conducted by introducing semiconducting metal oxides into SF to tailor its properties like conductivity for use as a gas sensing material, where SF acts as a conductive path as well as a substrate for the incorporated nanoparticles. We have reviewed gas and humidity sensing properties of silk, silk with 0D (i.e., metal oxide), 2D (e.g., graphene, MXenes) composites. The nanostructured metal oxides are generally used in sensing applications, which use its semiconducting properties to show variation in the measured properties (e.g., resistivity, impedance) due to analyte gas adsorption on its surface. For example, vanadium oxides (i.e., V2O5) have been shown as candidates for sensing nitrogen containing gases and doped vanadium oxides for sensing CO gas. In this review article we provide latest and important results in the gas and humidity sensing of SF and its composites

Selezione di razze di Bombyx mori ad alta efficienza nutrizionale e relative problematiche

The silkworm (Bombyx mori L.) is an insect belonging to the lepidopteran order, family Bombycidae: it is one of the two unique species belonging to the genus Bombyx, together with its ancestor – Bombyx mandarina Moore. In the past, silkworm exploitation in Europe was particularly related to the agricultural sector and the production of the silk thread but this type of activity has being disappearing from the old continent, in favour of some Asian countries, especially China, where cost of labour is low. In spite of the decline of these traditional activities the silkworm started to be used as a tool in a lot of technological applications and as a model in scientific research in various fields. Silk is regarded as a promising biomaterial because of its physical and chemical features both on the macro and microscale as well as in nano-technologies. Furthermore biology and biotechnology are interested in silkworm, or in its cell cultures, as a bioreactor to produce recombinant proteins which should otherwise be produced in bacteria or yeasts. The silkworm has a suitable size even for complex experiments with respect to other organisms used for the same aims, however it does not require large rearing rooms or high quantity of food, it can be easily reared under controlled conditions and its biological cycle is short (it lasts about 45 days), representing thus, also a model for basic research in life sciences. Moreover, to use the silkworm as a technological platform, important steps were achieved by sequencing the whole genome and by developing new optimized artificial diets for this insect (strictly monophagous), which freed rearing from seasonal constraints coming from mulberry leaf production in temperate climates. Thus, the above-mentioned new potentialities and a revived interest from the textile industry, about a silk supply chain outside Asia, establish the background of the research work described in this thesis. In fact, performed experiments relate with relaunching basic research activities about B. mori and aimed at meeting the needs of a silk industry, possibly developing in temperate countries. The starting material, that is the B. mori strains, belongs to the germplasm collection of Consiglio per la Ricerca e la sperimentazione in Agricoltura – Unità di ricerca di Apicoltura e Bachicoltura (CRA-API) of Padua and consists of about 200 strains, which differ in their phenotypic and genotypic characteristics. From the aforementioned collection, a selection process based on a mixed rearing strategy on both mulberry leaves and artificial diet has been started. The final goal was to select new strains characterized by high nutritional efficiency in order to optimize the cost-benefit ratio in all those application oriented to productivity. As already stated selection was based on a mixed approach: the first and more traditional step consisted in rearing silkworm larvae on mulberry leaf without any limitation in its quantity, by selecting only for the most important commercial parameters. On the other hand, the second step was a rearing cycle on artificial diet with a limited food amount fed to fifth instar larvae, followed by a selection process according to the most important productive traits. After three years and six generations of selection and genetic improvement, the obtained strains were compared among each other and with the unselected populations on the base of nutritional indexes which permitted an assessment of their conversion efficiency of proteins contained in the food matrix to body mass and silk. The final evaluation allowed to highlight the efficacy of the adopted strategy in selecting the desired features, although a difference related to diverse adaptability of the strains to the diet was recorded. In particular, for some of them, an additional preparatory step of selection on diet appears to be appropriate. During the period when experiments aimed at selection of highly efficient strains were performed, other relevant experimental data were produced. First of all, a new micro-organism which proved itself to be pathogenic for the silkworm reared on artificial diet was isolated and characterized; then, in-depth measurements about cold hardiness of eggs of a polyvoltine silkworm strain belonging to CRA-API’s collection were carried out. Described results to date do not represent the final goal but, an intermediate stage of a selection process that will continue at CRA-API and also, the starting point for the production of new hybrids with improved performances and suited to be reared on both mulberry leaf and artificialdiet

Unemployed: What Men\u27s And Women\u27s Divergent Experiences Tell Us About Gender Inequality

Over the last few decades, there has been tremendous progress toward gender equality. In recent years though, some scholars have suggested that this movement toward gender equality has stalled as women’s progress in various arenas, especially the home and in their labor-force participation, has plateaued. Scholars have thus focused their attention on ascertaining whether, where and for whom gender equality has stalled. Using family observation data as well as longitudinal in depth interviews with unemployed women, unemployed men, and their spouses, this dissertation argues that for this sample gender continues to powerfully shape life at home and orientations to the labor force. It shows that unemployed men’s unemployment experiences are central. Unemployment is perceived by unemployed men and their spouses as problematic, and in need of immediate rectification. During men’s unemployment, the home, family life and marital dynamics are organized so as to enable men to find re-employment. Alternatives to full-time paid employment are not considered. In contrast, the experience of demographically similar unemployed women is peripheral as their unemployment recedes to the backdrop of family life rather than being the center of it. Unemployed women do spend time job-searching, but they fit this into the schedule of their family life. Indeed, unemployed women often find themselves devoting extensive time to housework and childcare as they contend with being unemployed. Their husbands too emphasize that it is not imperative for women to find a job immediately, and they can take the time to focus on the home and children. Not all unemployed women’s experiences are equally peripheral. The cases that are less so nevertheless illuminate the gendered tensions between couples about the role of women’s paid employment in their marriage and family. These findings thus strongly support the idea of a gender stall for this sample. They show how, during the critical moment of unemployment, when gender rearrangements can be reconfigured and transformed in the home, the behaviors and attitudes of unemployed women, men, and their spouses, remain entrenched in normative notions of gender

Interfacial Assembly of Natural and Synthetic Components for Functional Bionanocomposites

Organized bionanocomposites are promising new materials since they are biocompatible, biodegradable, and can be used in a variety of applications such as flexible electronics, wearable sensors, and molecular sieving membranes. However, their mechanical and functional performance is not up to theoretical predictions due to a gap in understanding fundamental interactions between the biopolymeric and synthetic components of multilayered composite films. This work will focus on chemical and morphological changes of structural proteins in intimate contact with two-dimensional nanofillers when exposed to differing chemical environments and the resulting mechanical and conductive properties of multilayers composites. The first task aims to unveil the mechanisms behind silk fibroin’s natural morphological reorganization in direct contact with the surface of Ti3C2Tx MXene over time in aqueous solution. In the second task, the mechanical properties of silk-MXene multilayered composite films were investigated. Finally, suckerin-12 protein encapsulated MXene flakes are fabricated and their morphological reorganization in response to salt annealing was studied. These studies showed that MXene can be uniformly encapsulated by proteins with secondary structures that can be manipulated with non-covalent methods. Organized layered nanocomposites formed from these hybrid materials display enhanced mechanical properties dependent upon protein concentration and secondary structure. This work will inspire the fabrication of functional bionanocomposites with tailorable properties facilitated through interfacial interaction manipulation via non-covalent methods. These studies provide a framework for understanding interfacial interactions between structural proteins and two-dimensional synthetic materials and outlines techniques with which functional organized protein composites can be designed.Ph.D

Silk Macromolecules with Amino Acid–Poly(Ethylene Glycol) Grafts for Controlling Layer-by-Layer Encapsulation and Aggregation of Recombinant Bacterial Cells

This study introduces double-brush designs of functionalized silk polyelectrolytes based upon regenerated silk fibroin (SF), which is modified with poly-l-lysine (SF-PLL), poly-l-glutamic acid (SF-PGA), and poly(ethylene glycol) (PEG) side chains with different grafting architecture and variable amino acid-PEG graft composition for cell encapsulation. The molecular weight of poly amino acids (length of side chains), molecular weight and degree of PEG grafting (<i>D</i>) were varied in order to assess the formation of cytocompatible and robust layer-by-layer (LbL) shells on two types of bacterial cells (Gram-negative and Gram-positive bacteria). We observed that shells assembled with charged polycationic amino acids adversely effected the properties of microbial cells while promoting the formation of large cell aggregates. In contrast, hydrogen-bonded shells with high PEG grafting density were the most cytocompatible, while promoting formation of stable colloidal suspensions of individual cell encapsulates. The stability to degradation of silk shells (under standard cell incubation procedure) was related to the intrinsic properties of thermodynamic bonding forces, with shells based on electrostatic interactions having stronger resistance to deterioration compared to pure hydrogen-bonded silk shells. By optimizing the charge density of silk polyelectrolytes brushes, as well as the length and the degree of PEG side grafts, robust and cytocompatible cell coatings were engineered that can control aggregation of cells for biosensor devices and other potential biomedical applications