Question 1

Methods for transmission of zoonotic pathogens include:

Question 2

In the 20th century, decades of progress in reducing mortality due to acute infectious diseases was reversed due to

Question 3

Pregnant women and ___________experience the highest rates of malaria morbidity and mortality.

Question 4

The principle modes of transmission of hepatitis C (HCV) in low and middle income countries are believed to be:

Question 5

The causative agent for dengue fever is a:

Question 6

Both self-limited and persistent diarrhea can have a substantial and negative impact on child growth through which of the following mechanisms

Question 7

Underlying virtually every infectious disease of public health importance in low- and middle-income countries is the significant role played by poverty and its associated problems including

Question 8

It has been estimated that approximately_____of the world’s population is infected with M. tuberculosis.

Question 9

The definition of emerging zoonoses covers:

Question 10

True or false? Malaria is a disease caused by the parasitic Plasmodium protozoa.

True

False

Question 11

In what sense is influenza a zoonotic disease?

Question 12

Methods for the control of malaria include:

Question 13

Although malaria is found in 109 countries around the world, more than 80% of cases occur in:

Question 14

Identify the correct fact about rabies:

Question 15

_____________produces the most dramatic fluid losses of any enteric infection and causes death within 24-48 hours.

Question 16

True or false? Chronic infection contributes to the pathogenesis of a number of chronic diseases, such as certain cancers.

True

False

Question 17

________is the single most important predictor of developing pneumonia or lower respiratory tract infections.

Question 18

Children experience the highest risk of developing enteric infections between__________and then the risk declines steadily thereafter.

Question 19

The major known risk factors for morbidity and mortality from lower respiratory tract infections include low birth weight, age, malnutrition, not breastfeeding and________.

Question 20

The 1970’s saw the successful eradication of ___________ using a combination of enhanced case finding, containment and vaccination.

Question 21

Many international health professionals consider the most important contribution of public health in the 20th century and possibly in all of recorded history to be:

Question 22

The reduction of disease incidence, prevalence, morbidity or mortality to a locally acceptable level as a result of deliberate efforts is called:

Question 23

The most daunting challenges confronting the treatment and control of sexually transmitted infections (STIs) in low- and middle-income countries, beyond changing human behavior, include

Question

Follow the below statement and compile a formal report on the Wastewater treatment. The report should have following elements: title, table of content, list of tables, executive summary, introduction, main body, conclusion, recommendation, bibliography and properly numbered pages.

Wastewater Treatment Water Us

Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps and chemicals. In homes, this includes water from sinks, showers, bathtubs, toilets, washing machines and dishwashers. Businesses and industries also contribute their share of used water that must be cleaned.

Why Treat Wastewater?

There are a lot of good reasons why keeping our water clean is an important priority: fisheries, wildlife habitats, recreation and quality of life and health concerns.

If wastewater is not properly treated, then the environment and human health can be negatively impacted. These impacts can include harm to fish and wildlife populations, oxygen depletion, beach closures and other restrictions on recreational water use, restrictions on fish and shellfish harvesting and contamination of drinking water. Some examples of pollutants that can be found in wastewater and the potentially harmful effects these substances can have on ecosystems and human health:

• Decaying organic matter and debris can use up the dissolved oxygen in a lake so fish and other aquatic biota cannot survive;
• Excessive nutrients, such as phosphorus and nitrogen (including ammonia), can cause eutrophication, or over-fertilization of receiving waters, which can be toxic to aquatic organisms, promote excessive plant growth, reduce available oxygen, harm spawning grounds, alter habitat and lead to a decline in certain species;
• Chlorine compounds and inorganic chloramines can be toxic to aquatic invertebrates, algae and fish;

Wastewater treatment

The major aim of wastewater treatment is to remove as much of the suspended solids as possible before the remaining water, called effluent, is discharged back to the environment. As solid material decays, it uses up oxygen, which is needed by the plants and animals living in the water.

"Primary treatment" removes about 60 percent of suspended solids from wastewater. This treatment also involves aerating (stirring up) the wastewater, to put oxygen back in. Secondary treatment removes more than 90 percent of suspended solids.

The use of reclaimed wastewater helps people in two ways:

1. Reclaimed water can supply needed water for some purposes
2. Reclaimed wastewater frees up fresh water that can be used somewhere else, such as for drinking water

Uses of reclaimed wastewater

URBAN USES

Irrigation of public parks, sporting facilities, private gardens, roadsides; Street cleaning; Fire protection systems; Vehicle washing; Toilet flushing; Air conditioners; Dust control.

AGRICULTURAL USES

Food crops not commercially processed; Food crops commercially processed; Pasture for milking animals; Fodder; Fiber; Seed crops; Ornamental flowers; Orchards etc

RECREATIONAL USES

Golf course irrigation; Recreational impoundments with/without public access (e.g. fishing, boating, bathing); Aesthetic impoundments without public access; Snowmaking.

ENVIRONMENTAL USES

Aquifer recharge; Wetlands; Marshes; Stream augmentation; Wildlife habitat; Silviculture.

POTABLE (DRINKABLE) USES

Aquifer recharge for drinking water use; Augmentation of surface drinking water supplies; Treatment until drinking water quality.

THE PRIMARY TREATMENT PROCESS

1. Screening

Wastewater entering the treatment plant includes items like wood, rocks, and even dead animals. Unless they are removed, they could cause problems later in the treatment process. Most of these materials are sent to a landfill.

2. Pumping

The wastewater system relies on the force of gravity to move sewage from your home to the treatment plant. So wastewater-treatment plants are located on low ground, often near a river into which treated water can be released. If the plant is built above the ground level, the wastewater has to be pumped up to the aeration tanks (item 3). From here on, gravity takes over to move the wastewater through the treatment process.

3. Aerating

One of the first steps that a water treatment facility can do is to just shake up the sewage and expose it to air. This causes some of the dissolved gases (such as hydrogen sulfide, which smells like rotten eggs) that taste and smell bad to be released from the water. Wastewater enters a series of long, parallel concrete tanks. Each tank is divided into two sections. In the first section, air is pumped through the water.

4. Removing sludge

Wastewater then enters the second section or sedimentation tanks. Here, the sludge (the organic portion of the sewage) settles out of the wastewater and is pumped out of the tanks. Some of the water is removed in a step called thickening and then the sludge is processed in large tanks called digesters.

5. Removing scum

As sludge is settling to the bottom of the sedimentation tanks, lighter materials are floating to the surface. This 'scum' includes grease, oils, plastics, and soap. Slow-moving rakes skim the scum off the surface of the wastewater. Scum is thickened and pumped to the digesters along with the sludge.

6. Killing bacteria

Finally, the wastewater flows into a 'chlorine contact' tank, where the chemical chlorine is added to kill bacteria, which could pose a health risk, just as is done in swimming pools. The chlorine is mostly eliminated as the bacteria are destroyed, but sometimes it must be neutralized by adding other chemicals. This protects fish and other marine organisms, which can be harmed by the smallest amounts of chlorine.

1.Consumers spraying their lawns for control of white grubs with the formulation Dursban prior to its removal from hardware stores like Home Depot and Ace were estimated to have a high end exposure of about 0.015 mg/kg/day. Considering that this product would only be applied once or twice a growing season, the margin of exposure (MOE) relative to the acute no observable adverse effect level (NOEL or NOAEL) of 0.5 mg/kg/day is [______]. This exposure is [_______] (above or lower) EPAs levels of concern (LOC).

2. Although Roundup is more toxic than its active ingredient alone, cause for concern should a wetland be oversprayed is unlikely due to a short persistence time of the toxicant causing this differential effect. The reason for this short persistence time is the presence in natural waters of [__________________].

3. The work of Tyrone Hayes at the University of California-Berkeley has suggested that atrazine herbicide disrupts the endocrine system. Some scientists suggest therefore that frogs should be used as “canaries in a coal mine” and forewarn us about the imminent danger that this herbicide poses to human fertility and development. The plausibility of such an extrapolation is weak for which of the following reasons. (Choose all reasons that support the lack of plausibility)

a.The aggregate of all research on atrazine in a quantitative weight of evidence meta analysis concluded that effects on amphibian development and growth were unlikely

b. Studies published subsequent to Hayes early research were not able to repeat the observations of effects on frogs

c. Atrazine residues are hardly ever found in food, thus exposures would be minimized.

d. Atrazine residues are hardly ever found in water, thus exposures would be minimized.

Estimating the time of a victim’s death during homicide investigations is a complex problem that cannot be solved by analysising simple equations or functions of one variable. However, many mathematical texts examine time of death estimation based around analysis of Newton’s Law of Cooling. Such analysis is based on implicit simplifying assumptions that: the only dependent variable of interest in determining the time of death is the victim’s body temperature, T(t); the victim’s baseline body temperature when alive, T0, is known; and the air temperature of the victim’s surroundings, Ts, is constant. Here we will examine such a problem.

(a) Assume that immediately following death, a victim’s body begins to cool from a standard healthy body temperature of 37◦ Celsius. Further, assume that experimental work has determined that the rate constant in Newton’s Law of Cooling for a human body is approximately k = 0.1947 when time t is measured in hours. Determine a function derived from Newton’s Law of Cooling, T(t), that models the temperature of a victim’s body t hours after death, assuming that the temperature of the body’s surroundings is a constant 15.5◦ Celsius

. (b) If the temperature of the victim’s body is now 22.2◦, how long ago was their time of death? (c) If the victim’s body temperature at death had instead been 36.3◦ Celsius (within the range of normal body temperatures for a healthy adult), what time of death would be estimated via a Newton’s Law of Cooling model? By what duration does this estimate differ to the time that you determined in part

(b)? (d) In reality, how might the modelling assumptions made to address this problem be violated?

Thirdhand smoke (THS) is the fraction of cigarette smoke that persists in indoor environments after smoking. We investigated the effects of neonatal and adult THS exposure on bodyweight and blood cell populations in C57BL/6 J mice. At the end of neonatal exposure, THS-treated male and female mice had significantly lower bodyweight than their respective control mice. However, five weeks after neonatal exposure ended, THS-treated mice weighed the same as controls. In contrast, adult THS exposure did not change bodyweight of mice. On the other hand, both neonatal and adult THS exposure had profound effects on the hematopoietic system. Fourteen weeks after neonatal THS exposure ended, eosinophil number and platelet volume were significantly higher, while hematocrit, mean cell volume, and platelet counts were significantly lower compared to control. Similarly, adult THS exposure also decreased platelet counts and increased neutrophil counts. Moreover, both neonatal and adult THS exposure caused a significant increase in percentage of B-cells and significantly decreased percentage of myeloid cells. Our results demonstrate that neonatal THS exposure decreases bodyweight and that THS exposure induces persistent changes in the hematopoietic system independent of age at exposure. These results also suggest that THS exposure may have adverse effects on human health.

1. Do the data support the author’s conclusions? Which findings were used to support specific conclusion(s) and why do such findings support this conclusion (rather than some other conclusion) Specifically link three results with the conclusion they support.

Question 214 pts

If the world price is above the domestic “no-trade” equilibrium price, then with international trade, the shortage caused in the domestic market can be met by foreign imports.

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Question 224 pts

Firms in industrial countries find a larger market for their goods in other industrial countries than in developing countries because:

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Question 234 pts

A country benefits from trade if it is able to obtain a good from a foreign country:

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Question 244 pts

We know that industrial countries tend to trade with other industrial countries. This pattern counters the:

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Question 254 pts

It seems evident that countries would have an advantage in producing those goods that use relatively large amounts of their most abundant factor of production.