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You can get them to work for free, they will ask "How high? Examines relationship among areas of development and the connection between development and children's behaviors. Posted by Spider March 22, 1: Peptide synthesis and Peptide bond. Educational structures, practices, and projections for the future will be studied.
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BONE , 16 1 BRAIN , 1 1 BURNS , 21 1 CELL , 1 1 Cloning and Stem Cells. CASES , EMJ , 1 1 Environmental Pollution Series A.. Environment Systems and Decisions. Evolution and Human Behavior. European Journal of Nuclear Fungal Genetics and Biology. FOOT , 5 1 GELS , 1 1 Gratis. GENE , 1 1 The Holarctic genus Pityokteines contains nine species, six of them from the Nearctic and the other three from the Palaearctic. Most of them feed on Abies, although one North American species, P.
Pityokteines curvidens was described by Germar in as Tomicus curvidens. The generic designation Pityokteines dates from Fuchs, and P. Description Top of page Eggs The eggs are whitish and translucent, with a thin shiny chorion.
Larvae Larvae are, apodous, with a whitish body and dark head. The mature larvae reach about 4 mm in length see Pictures. Pupa Pupae are of the exarate type, whitish and bright, bearing two caudal spines. They can reach 3. No morphological studies of pupae are known. Adults Adults are evenly blackish with antennae and legs yellowish-brown and with marked sexual dimorphism. Integumental surface bright, including the elytral declivity. Pronotum bearing spiculae not rising much from the surface; they are bright and irregularly spaced; in the basal part, they are replaced by a clear punctuation but a wide median strip is bright and smooth; the highest part of pronotum is in the centre where spines are replaced by punctures; the pubescence on pronotum is abundant, the one between the spiculae with apex curved posteriorly, the one on the basal half with apex curved anteriorly.
The elytral striae have rows of punctures that progressively increase in diameter and depth towards the elytral declivity. Pubescence on elytral declivity long and straight.
Sutural interstria slightly protruding, with a regular row of setae on both sides of sutura. Males bearing three pairs of prominent denticles on the elytral declivity; sutural denticle vertical with apex sometimes directed anteriorly; the median tooth is strongest, hook-shaped, with rounded apex directed towards the suture and inferiorly; apical tooth with a regularly increasing diameter, slightly curved superiorly with pointed apex.
Frons bearing sparse and fine pubescence see Pictures. Females with teeth on the elytral declivity reduced and approximately the same shape. Frons with small median prominence and dense tuft of long yellow hairs protruding towards anterior margin of pronotum. Hairs on frons and pronotum of the same length. Metasternum and abdominal sternites bearing long yellow hairs sloping posteriorly, similar to those on the upper surface.
Wing with anal lobe well separated from the rest of wing surface by a deep, wide retraction of the margin. Distribution Top of page P. Distribution Table Top of page The distribution in this summary table is based on all the information available. According to Schedl , the reports by Kleine , referring to Greenland, South Africa and Argentina but not confirmed by more recent records, are probably invalid and based on misidentification. Risk of Introduction Top of page The phytosanitary hazard related to P.
The main causes of bark beetle outbreaks are long dry spells, which are becoming increasingly frequent in southern regions of Europe Kailidis and Markalas, ; Rieder, ; Tsankov et al. Other trees which serve as hosts to P. Growth Stages Top of page Vegetative growing stage. Symptoms Top of page The beginning of an attack on a tree by P. The diameter of the entrance holes is about 1. The change of the normal canopy colour to light-yellow at first and then red usually takes about two months see pictures.
Biology and Ecology Top of page The literature on the biology and ecology of Pityokteines curvidens is very rich, the most important papers being those by Kraemer , Chararas ; , Kailidis and Georgevits , Vasechko and Harring Physiology and phenology P.
However, it can also survive the winter under the bark healthy firs, somewhat damaging the infested trees Braun, b. It frequently overwinters in the larval or pupal stages; in fact it is possible to find parent beetles, differently aged larvae, as well as pupae and newly emerged adults under the bark at the same time. The pupal stage is the most vulnerable to low temperatures. Adults leave the winter sites and start their reproductive phase from the second half of April or somewhat later according to the climatic conditions, altitude and exposure of the stands Cecconi, ; Chararas, When there are two generations, the second one starts in August.
After finding suitable trees to colonise, the pioneer males start boring their galleries under the bark, where they feed on living tissues. After 24 to 36 hours of feeding, they begin to release the aggregation pheromone via their frass; the main component is S-ipsenolo S methylmethyleneoctenol.
Only males release this pheromone, which repels the other two congeneric species, P. Thus they rarely colonise the same tree. The gallery system usually lacks a distinct nuptial chamber hollowed in the alburnum see Pictures , unlike that of the other congeneric Palaearctic species see Pictures.
The entrance hole is followed by a longitudinal chamber cm long; from its end, the females start digging their transverse tunnels, cm long, slightly hollowing the alburnum. When there is only one male and two females, the gallery system scheme is the classic double horizontal brace see Pictures ; however, depending on the number of females, it can sometimes be asymmetrically incomplete or more intricate.
Each female can lay eggs in niches hollowed with their mandibles on both sides of the maternal gallery. After the first egg-laying and after feeding again, the females can dig another short tunnel and lay other eggs, starting a new, delayed generation Chararas, ; Pennacchio et al.
Embryonic development can last six days on trees in sunny stands up to m altitude, but can extend to 17 days at higher altitude or on shaded firs. The larvae start feeding and digging galleries, cm long, orthogonal to the maternal ones see Pictures ; their development can last from 30 to 50 days depending on the same environmental factors.
When mature, the larvae bore into the alburnum, reaching a depth of mm, where they dig the pupal cell 6 x 2 mm. There they change into pupae and days later into adults see Pictures. The adults emerge from the tree bark after feeding on phloem tissues for days the maturation phase during which they attain their definitive dark brown colour Chararas, Armillaria due to either waterlogging or a prolonged dry spells. The latter is more frequent in the southern areas of the geographical range of Abies alba, i.
Colonization of a new host plant starts from the tip and then reaches the base. Even very old trees with thick bark can be attacked. On the same trees, we also usually find the weevil Pissodes piceae and the cerambycids Rhagium inquisitor, Corymbia rubra and Anastrangalia dubia.
Other organisms, such as nematodes, have a phoresic interrelationship with P. Aphelenchoididae they have no phytosanitary importance in their native areas , Fucsia sp. Diplogasteridae , Parasitorhabditis sp. Rhabditidae , Ditylenchus pityokteinophilus Nematoda: Many species of mites also have a phoresic interrelationship with P. Most of them prey on the larvae of P. There are a large number of parasitoid records from P. A microsporidian infection caused by the protozoan Nosema curvidentis Weiser was found in a natural population of P.
The natural mortality of P. Means of Movement and Dispersal Top of page P. Impact Top of page Colonization by P. Economic evaluations of the damage caused by this bark beetle are not yet available. However, there are many literature reports of economic losses in central Europe attributed to P.
Economic Impact Top of page Colonization by P. Detection and Inspection Top of page It is recommended that attacked plants be identified at the beginning of colonization by this scolytid beetle, when boring dust is observed coming out of the entrance holes being dug by males or when the canopy is starting to change colour.
In this way, forest management practices can be planned ad hoc before the new adults emerge and fly. They can be separated according to the following key. Key to the European species of Pityokteines 1 Frons slightly pubescent with a few hairs.
Elytral declivity with a pair of small but distinct sutural denticles; it bears a second pair of large, more or less hook-shaped denticles and a pair of conical denticles at apex. Strial punctures progressively increasing in diameter from basis to elytral declivity males Go to 2. Frons and anterior pronotal margin with dense pubescence of very long, yellow-golden hairs. Elytral declivity with 3 pairs of small protuberances. Strial punctures progressively increasing in diameter from basis to elytral declivity females Go to 4.
Quadrangular surface between the second and third pair of denticles. Strial punctures slightly increasing in diameter from basis to apex of elytrae; flat interstriae with punctures along their entire length, reaching the declivity. Transverse rectangular area between the second and third pair of denticles. Strial punctures progressively and strongly increasing in diameter toward apex; interstriae without punctures before the elytral declivity.
Median hook isodiametric for its entire length, but apex is short, restricted, with a blunt tip. Median hook progressively thinner from basis to apex. Anterior pronotal margin with hairs clearly longer than those of the frons. Strial punctures slightly increasing in diameter from basis to apex. Large flat interstriae with punctures reaching the declivity. Quadrangular space between second and third pair of protuberances on elytral declivity.
Space between second and third pair of protuberances on elytral declivity is a transverse rectangle. Strial punctures strongly increasing in diameter toward the apex.
Interstriae narrow, starting from the middle of elytrae, without punctures before the declivity. Prevention and Control Top of page Culture control and sanitary methods. The most suitable forest management practice would be to mix Abies with broadleaved trees such as Fagus sylvatica, Acer pseudoplatanus, A. In mature stands, trees attacked by the bark beetle, as well those uprooted, split, otherwise, should be cut and removed Schneider-Orelli and Kuhn ; Schneider-Orelli and Maksymov, It may also be useful to de-bark the infested trunks before the larvae reach maturity and dig-out their pupal cells from the alburnum.
The use of trap trees, perhaps baited with the aggregation pheromone, could be profitable, especially before the emergence and flight of the bark beetle adults. No measures of biological control of P. Focusing on improving the aesthetics and community relationships and not only on the plant yield, is the best way to maximize the positive effect of urban farms on a neighborhood.
Using high-density urban farming, as for instance with vertical farms or stacked greenhouses, many environmental benefits can be achieved on a citywide scale that would be impossible otherwise. These systems do not only provide food, but also produce potable water from waste water, and can recycle organic waste back to energy and nutrients.
A report by the USDA, determined that "Evidence is both abundant and robust enough for us to conclude that Americans living in low-income and minority areas tend to have poor access to healthy food", and that the "structural inequalities" in these neighborhoods "contribute to inequalities in diet and diet-related outcomes". Not only can urban agriculture provide healthy, fresh food options, but also can contribute to a sense of community, aesthetic improvement, crime reduction, minority empowerment and autonomy, and even preserve culture through the use of farming methods and heirloom seeds preserved from areas of origin.
Urban agriculture may advance environmental justice and food justice for communities living in food deserts. When urban agriculture leads to locally grown fresh produce sold at affordable prices in food deserts, access to healthy food is not just available for those who live in wealthy areas, thereby leading to greater equity in rich and poor neighborhoods.
Improved access to food through urban agriculture can also help alleviate psychosocial stresses in poor communities. Community members engaged in urban agriculture improve local knowledge about healthy ways to fulfill dietary needs. Urban agriculture can also better the mental health of community members.
Buying and selling quality products to local producers and consumers allows community members to support one another, which may reduce stress. Thus, urban agriculture can help improve conditions in poor communities, where residents experience higher levels of stress due to a perceived lack of control over the quality of their lives. Urban agriculture may improve the livability and built environment in communities that lack supermarkets and other infrastructure due to the presence of high unemployment caused by deindustrialization.
Urban farmers who follow sustainable agriculture methods can not only help to build local food system infrastructure, but can also contribute to improving local air, and water and soil quality.
Sustainable urban agriculture can also promote worker protection and consumer rights. However, urban agriculture can also present urban growers with health risks if the soil used for urban farming is contaminated. Although local produce is often believed to be clean and healthy, many urban farmers ranging from New York urban farmer Frank Meushke  to Presidential First Lady Michelle Obama  have found their products contained high levels of lead , due to soil contamination , which is harmful to human health when consumed.
The soil contaminated with high lead levels often originates from old house paint which contained lead, vehicle exhaust , or atmospheric deposition. Without proper education on the risks of urban farming and safe practices, urban consumers of urban agricultural produce may face additional health-related issues . Creating a community-based infrastructure for urban agriculture means establishing local systems to grow and process food and transfer it from farmer producer to consumer.
To facilitate food production, cities have established community-based farming projects. Some projects have collectively tended community farms on common land , much like that of eighteenth-century Boston Common. Other community garden projects use the allotment garden model, in which gardeners care for individual plots in a larger gardening area, often sharing a tool shed and other amenities.
Independent urban gardeners also grow food in individual yards and on roofs. Garden sharing projects seek to pair producers with the land, typically, residential yard space. Roof gardens allow for urban dwellers to maintain green spaces in the city without having to set aside a tract of undeveloped land. Rooftop farms allow otherwise unused industrial roofspace to be used productively, creating work and profit.
Food processing on a community level has been accommodated by centralizing resources in community tool sheds and processing facilities for farmers to share.
Different areas of the city have tool banks where resources like tools, compost , mulch, tomato stakes, seeds, and education can be shared and distributed with the gardeners in that cluster.
Detroit's Garden Resource Program Collaborative also strengthens their gardening community by providing to their member's transplants; education on gardening, policy, and food issues; and by building connectivity between gardeners through workgroups, potlucks, tours, field trips, and cluster workdays.
In Brazil, "Cities Without Hunger" has generated a public policy for the reconstruction of abandoned areas with food production and has improved the green areas of the community. Farmers' markets , such as the farmers' market in Los Angeles , provide a common land where farmers can sell their product to consumers. Large cities tend to open their farmer's markets on the weekends and one day in the middle of the week.
However, to create a consumer dependency on urban agriculture and to introduce local food production as a sustainable career for farmers, markets would have to be open regularly. For example, the Los Angeles Farmers' Market is open seven days a week and has linked several local grocers together to provide different food products.
The market's central location in downtown Los Angeles provides the perfect interaction for a diverse group of sellers to access their consumers. In Queensland many people have started a trend of urban farming both utilizing Aquaponics and self-watering containers. In Egypt, development of rooftop gardens began in the s. In the early s at Ain Shams University , a group of agriculture professors developed an initiative focused on growing organic vegetables to suit densely populated cities of Egypt.
The initiative was applied on a small scale; until it was officially adopted in , by the Food and Agriculture Organization FAO. After the disintegration of the Soviet Union and the Eastern Bloc , Cuba faced severe shortages of fuel and agrochemical inputs. These products had previously been imported from the Soviet Union in exchange for Cuban sugar. As a result, Cubans experienced an acute food crisis in the early s, which in part was met with a popular movement of urban agriculture.
Urban farmers employed — and still employ — agroecological techniques, allowing food production to take place largely without petroleum-based inputs. In , more than , Cubans worked in the expanding urban agriculture sector. Economic development in Mumbai brought a growth in population caused mainly by the migration of laborers from other regions of the country.
The number of residents in the city increased more than twelve times in the last century. In this scenario, urban agriculture seems unlikely to be put into practice since it must compete with real estate developers for the access and use of vacant lots. Alternative farming methods have emerged as a response to the scarcity of land, water, and economic resources employed in UPA.
Doshi's city garden methods are revolutionary for being appropriate to apply in reduced spaces as terraces and balconies, even on civil construction walls, and for not requiring big investments in capital or long hours of work. His farming practice is purely organic and is mainly directed to domestic consumption.
His gardening tools are composed of materials available in the local environment: The containers and bags open at both ends are filled with the sugarcane stalks, compost, and garden soil, which make possible the use of a minimal quantity of water is compared to open fields.
Doshi states that solar energy can replace soil in cities. He also recommends the idea of chain planning, or growing plants in intervals and in small quantities rather than at once and in large amounts. The concept of city farming developed by Dr. Doshi consumes the entire household's organic waste. He subsequently makes the household self-sufficient in the provision of food: The main objectives of a pilot project at city farm at Rosary High School, Dockyard Road, were to promote economic support for street children, beautify the city landscape, supply locally produced organic food to urban dwellers mainly those residing in slums , and to manage organic waste in a sustainable city.
The project was conducted in the Rosary School, in Mumbai, with the participation of street children during The participants were trained in urban farming techniques. The farm produced vegetables, fruits, and flowers. The idea has spread the concept of city farm to other schools in the city. The Mumbai Port Trust MBPT central kitchen distributes food to approximately 3, employees daily, generating important amounts of organic disposal.
A terrace garden created by the staff recycles ninety percent of this waste in the production of vegetables and fruits. The activity of city farming was started initially to dispose of kitchen organic waste in an eco-friendly way.
Staff members, after their daily work in the kitchen, tend the garden, which has about plants. While the goals of the NGO are important in a global context, the community goals are being met through the work of forming the urban gardens themselves.
In this sense, the creation, implementation, and maintenance of urban gardens are highly determined by the desires of the communities involved. However, the criteria by which TEI measured their success illustrates the scope of benefits to a community which practices urban agriculture.
TEI's success indicators were:. Recently, with relative food security in China, periurban agriculture has led to improvements in the quality of the food available, as opposed to quantity. One of the more recent experiments in urban agriculture is the Modern Agricultural Science Demonstration Park in Xiaotangshan.
Traditionally, Chinese cities have been known to mix agricultural activities within the urban setting. Shenzhen, once a small farming community, is now a fast-growing metropolis due to the Chinese government designation as an open economic zone. Due to large and growing population in China, the government supports urban self-sufficiency in food production.
Shenzhen's village structure, sustainable methods, and new agricultural advancements initiated by the government have been strategically configured to supply food for this growing city.
The city farms are located about 10 kilometres 6. The first tier approached from city center produces perishable items. Located just outside these farms, hardier vegetables are grown such as potatoes, carrots, and onions. This system allows producers to be sold in city markets just a few short hours after picking.
Another impressive method used in Chinese agriculture and aquaculture practice is the mulberry-dike fish-pond system, which is a response to waste recycling and soil fertility.
This system can be described as: Mulberry trees are grown to feed silkworms and the silkworm waste is fed to the fish in ponds. The fish also feed on waste from other animals, such as pigs, poultry, and buffalo.
The animals, in turn, are given crops that have been fertilized by mud from the ponds. This is a sophisticated system as a continuous cycle of water, waste, and food As the population grows and industry advances, the city tries to incorporate potential agricultural growth by experimenting with new agricultural methods.
This farm was established with aspirations of producing large quantities and high-quality lychees, by constantly monitoring sugar content, and their seeds. This research, conducted by local agricultural universities allows for new methods to be used with hopes of reaching the needs of city consumers.
However, due to increased levels of economic growth and pollution, some urban farms have become threatened. The government has been trying to step in and create new technological advancements within the agricultural field to sustain levels of urban agriculture.
According to the Municipal Bureau of Agriculture, Forestry and Fishery the city will invest million yuan on farms located around the city, with hopes of the farms to provide "60 percent of the meat, vegetables, and aquatic products in the Shenzhen market". There has also been an emerging trend of going green and organic as a response to pollution and pesticides used in farming practices. Vegetable suppliers are required to pass certain inspections held by the city's Agriculture Bureau before they can be sold as "green".
Harare is particularly suited for urban agriculture, as its topography heavily features vleis , land drainage systems that become waterlogged in the rainy season. When it rains they are difficult to cross, and in the dry season they shrink and crack, which causes structural damage to infrastructure, even though the vleis are still storing water underground. Therefore, these moisture-rich areas are mostly left unbuilt, allowing for urban cultivation.
Aside from vleis and the private residential land that Harareans cultivate, considerable public land is used for agriculture in Harare: However, urban agriculture in Harare causes harm to the environment. The practice has reduced rainwater infiltration into the soil by In the s, the failure of Structural Adjustment Programs induced greater unemployment, higher prices, and lower incomes, so more people started growing their own food.
The practice continued in the s when a major recession brought about widespread poverty, unemployment, and enormous inflation. Finally, the Nyanga Declaration on Urban Agriculture in Zimbabwe explicitly acknowledged the value of urban agriculture for food security and the reduction of poverty. Accepting that many people depend on it to survive, the government allocated sixty thousand hectares of land in Harare for cultivation purposes.
In New York City , many low-income residents suffer from high rates of obesity and diabetes and limited sources of fresh produce.
The City and local nonprofit groups have been providing land, training and financial encouragement, but the impetus in urban farming has really come from the farmers, who often volunteer when their regular work day is done.
Eligible projects include green roofs, rooftop farms, and rainwater harvesting on private property in combined sewer areas. Because of this grant program, New York City now has the world's largest rooftop farms. Some urban gardeners have used empty lots to start a community or urban gardens.
However, the soil must be tested for heavy contamination in city soil because of vehicle exhaust and remnants of old construction. The City also has a composting program, which is available to gardeners and farmers. One group, GreenThumb, provides free seedlings. Another program, the City Farms project operated by the nonprofit Just Food, offers courses on growing and selling food. Two alternate means of growing are rooftop gardens and hydroponic soil-less growing. The New York Times wrote an article about one of Manhattan's first gardens which incorporate both these techniques.
In response to the recession of , a coalition of community-based organizations, farmers, and academic institutions in California's Pomona Valley formed the Pomona Valley Urban Agriculture Initiative.
After the passage of the North American Free Trade Agreement , cheap grain from the United States flooded Mexico, driving peasant farmers off of their land. Many immigrated to the Pomona Valley and found work in the construction industry.
With the recession, the construction industry also suffered in the region. It is unlikely to regain its former strength because of severe water shortages in this desert region as well as ongoing weakness in the local economy. These immigrants were dry land organic farmers in their home country by default since they did not have access to pesticides and petroleum-based fertilizers. Now, they found themselves on the border of two counties: Los Angeles County with a population of 10 million and almost no farmland, and San Bernardino County which has the worst access to healthy food in the state.
In response to these conditions, Uncommon Good, a community-based nonprofit organization that works with immigrant farmer families, convened a forum which became the Urban Farmers Association. The Urban Farmers Association is the first organization of its kind for poor immigrant farmers in the Pomona Valley. Its goal is to develop opportunities for its members to support themselves and their families through urban agriculture.